lib/jvm: prevents string warnings on JVM

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
lib/jvm: support the Android platform by desactivating unavailable features

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
lib/jvm: adapt Jvm::attach_current_thread to Android

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
java ffi: use Java int to store C pointers

While long worked with OpenJDK on linux, it did not on Android.

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
android: support FFI with Java

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
android: enable code in AndroidManifest

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
lib: intro the load_jclass method

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
nitg: use load_jclass in Java FFI

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
lib/mnit_android: intro App::native_activity

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
examples/mnit_simple: test Android log and toasts

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
lib: fix find_class_loader with latest FFI spec

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
Merge branch 'master' into java-ffi-android
Merge: Java FFI on Android

The FFI needed some modifications to work on Android:
* Android does not implement the full JNI (so we deactivate them)
* Its implementation does not expose the same signatures as OpenJDK's
* Provide our own load_jclass because we need a specific class loader (JNI's FindClass is no enough on Android)
* Using Dalvik's long corrupted data going through Java (more debugging will be needed, anyway we can use Ints to hold pointers to C objects)

In the API, intro `App::native_activity` as a shortcut to get the main android Activity.

Update mnit_simple to use Java on Android.

Pull-Request: #418
Reviewed-by: Jean Privat <jean@pryen.org>