Many units here are a simple translation of Android NDK C headers to Pascal,
copies from Lazarus and cleaned up a little,
see trunk/lcl/interfaces/customdrawn/android/ in Lazarus sources.

Note that castleandroidnativeactivity.pas needed a fix:
{$linklib android}, otherwise it cannot be loaded (unresolved symbols,
resulting in enigmatic messages in logcat:
java.lang.RuntimeException: Unable to start activity ComponentInfo{net.sourceforge.castleengine.cgeandroidtest/android.app.NativeActivity}: java.lang.IllegalArgumentException: Unable to load native library: /data/data/net.sourceforge.castleengine.cgeandroidtest/lib/libcge_android_lib.so
).

For information about the Android NDK API, see
http://developer.android.com/tools/sdk/ndk/index.html
