Various fixes to the build scripts (*.bat & *.sh)

build.readme.md: mention how to build the native libs when on windows

Fix target name: rename target to keepass2android-app

*.BAT build-scripts: make script fail when a command fails
  If a command was failing, the script continued to run and didn't fail.
  The build errors could be hidden. This will make them apparent

build-java.bat:
- prefix call to gradlew.bat with 'call'
  Otherwise, the batch file stops at the first gradlew call.
- don't build PluginQR as its output is not used, and the build fails with
  newer Android SDK/NDK

build-xamarin.bat:
- use VS2019 path, download NuGet dependencies
- Call vcvarsall.bat only if not yet done
- build also APK
- Tested with VS Community 2019
- When calling it multiple times, the PATH env var contains duplicate values
  and in the end will be too long, leading to vcvarsall.bat failing,
  and hence build-xamarin.bat too

build-java.sh:
- don't unset ANDROID_NDK_HOME & ANDROID_NDK
  Fixes build issues on github actions
- add missing KP2AKdbLibrary
- add executable bit to src/java/KP2AKdbLibrary/gradlew
- support build with msbuild & force use of xabuild when on linux
- don't build PluginQR as its output is not used, and the build fails with
  newer Android SDK/NDK

build-xamarin.sh:
- put the config (Debug or Release) in a variable

build-apk.sh:
- fix project name to keepass2android-app.csproj
- support build with msbuild & force use of xabuild when on linux
  Needed for github actions, and will also support building on macos with msbuild
- put the config (Debug or Release) in a variable
- Add missing /p:Configuration= /p:Platform=AnyCPU which is needed when building
  nonet on macos (because nonet uses "Release")

remove PluginQR

src/build-scripts/build-apk.sh

@@ -3,12 +3,26 @@ set -e
 
 pushd ../keepass2android
 
+# Determine if we use msbuild or xabuild to build.
+if which msbuild > /dev/null; then
+  if [ $(uname) == "Linux" ]; then
+    # For now, when running on Linux, we can't use msbuild but have to use xabuild (provided by https://github.com/xamarin/xamarin-android)
+    BUILDER=xabuild
+  else
+    BUILDER=msbuild
+  fi
+else
+  BUILDER=xabuild
+fi
+
+CONFIG=Debug
+
 # check if ANDROID_HOME is defined
 if [ -z ${ANDROID_HOME+x} ];
 then
-	xabuild keepass2android.csproj /t:SignAndroidPackage "$@"
+	$BUILDER keepass2android-app.csproj /t:SignAndroidPackage /p:Configuration="$CONFIG" /p:Platform=AnyCPU "$@"
 else
-	xabuild keepass2android.csproj /p:AndroidSdkDirectory=$ANDROID_HOME /t:SignAndroidPackage "$@"
+	$BUILDER keepass2android-app.csproj /p:AndroidSdkDirectory=$ANDROID_HOME /t:SignAndroidPackage /p:Configuration="$CONFIG" /p:Platform=AnyCPU "$@"
 fi
 
 popd

src/build-scripts/build-java.bat

@@ -1,20 +1,15 @@
 cd ..\java\JavaFileStorageTest-AS
-./gradlew clean assemble
+call ./gradlew clean assemble || exit /b
 cd ..\..\build-scripts
 
 cd ..\java\KP2ASoftkeyboard_AS
-./gradlew clean assemble
+call ./gradlew clean assemble || exit /b
 cd ..\..\build-scripts
 
 cd ..\java\Keepass2AndroidPluginSDK2
-./gradlew clean assemble
+call ./gradlew clean assemble || exit /b
 cd ..\..\build-scripts
 
 cd ..\java\KP2AKdbLibrary
-./gradlew clean assemble
+call ./gradlew clean assemble || exit /b
-cd ..\..\build-scripts
-
-cd ..\java\PluginQR
-./gradlew clean assemble
-
 cd ..\..\build-scripts

src/build-scripts/build-java.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 set -e
 
-unset ANDROID_NDK_HOME ANDROID_NDK
+#unset ANDROID_NDK_HOME ANDROID_NDK
 
 pushd ../java/
 
@@ -17,7 +17,7 @@ pushd Keepass2AndroidPluginSDK2
 ./gradlew assemble
 popd
 
-pushd PluginQR
+pushd KP2AKdbLibrary
 ./gradlew assemble
 popd
 

src/build-scripts/build-xamarin.bat

@@ -9,8 +9,17 @@ cd ..\..\keepass2android
 call UseManifestDebug.bat
 cd ..
 
-call "C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\vcvarsall.bat" x86_amd64
+IF NOT "%VSCMD_VCVARSALL_INIT%" == "1" (
+  call "C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvarsall.bat" x86_amd64
+)
 
-msbuild KeePass.sln /target:keepass2android /p:BuildProjectReferences=true /p:Configuration="Debug" /p:Platform="Any CPU"
+REM Download NuGet dependencies
+msbuild KeePass.sln -t:restore -p:RestorePackagesConfig=true || exit /b
 
-cd build-scripts
+REM Build
+set CONFIG=Debug
+msbuild KeePass.sln /target:keepass2android-app /p:BuildProjectReferences=true /p:Configuration="%CONFIG%" /p:Platform="Any CPU" /p:AndroidBuildApplicationPackage=True || exit /b
+
+cd build-scripts
+
+echo apk can be found in src\keepass2android\bin\%CONFIG%

src/build-scripts/build-xamarin.sh

@@ -20,12 +20,26 @@ popd
 
 # call "C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\vcvarsall.bat" x86_amd64
 
+# Determine if we use msbuild or xabuild to build.
+if which msbuild > /dev/null; then
+  if [ $(uname) == "Linux" ]; then
+    # For now, when running on Linux, we can't use msbuild but have to use xabuild (provided by https://github.com/xamarin/xamarin-android)
+    BUILDER=xabuild
+  else
+    BUILDER=msbuild
+  fi
+else
+  BUILDER=xabuild
+fi
+
+CONFIG=Debug
+
 # check if ANDROID_HOME is defined
 if [ -z ${ANDROID_HOME+x} ];
 then
-	xabuild KeePass.sln /target:keepass2android /p:BuildProjectReferences=true /p:Configuration="Debug" /p:Platform="Any CPU" "$@"
+	$BUILDER KeePass.sln /target:keepass2android-app /p:BuildProjectReferences=true /p:Configuration="$CONFIG" /p:Platform="Any CPU" "$@"
 else
-	xabuild KeePass.sln /target:keepass2android /p:AndroidSdkDirectory=$ANDROID_HOME /p:BuildProjectReferences=true /p:Configuration="Debug" /p:Platform="Any CPU" "$@"
+	$BUILDER KeePass.sln /target:keepass2android-app /p:AndroidSdkDirectory=$ANDROID_HOME /p:BuildProjectReferences=true /p:Configuration="$CONFIG" /p:Platform="Any CPU" "$@"
 fi
 
 popd

src/build.readme.md

@@ -15,7 +15,12 @@ To build KP2A from scratch, make sure that you have Xamarin's Mono for Android i
 ## Build
 
 ### On Windows
-
+From within the `src` directory, build the native lib with:
+```bat
+cd java/argon2
+%ANDROID_NDK_ROOT%/ndk-build.cmd
+```
+Then, from within the `src` directory run:
 ```bat
 cd build-scripts
 build-java.bat