ae-bridge: Initial commit.

Starting to consolidate all paulscode-specific code into a pair of
shared libraries (exports = Java->C, imports = C->Java).  A pair is
necessary due to the dependency graph with SDL, core, and front-end.

              { SDL             }
ae-imports <- {  ^ core         } <- ae-exports
              {     ^ front-end }

The goal is to minimize the upstream diff, and to simplify upstream
synchronizations and creation/replacement of plugins/dependencies.
ae-bridge: Consolidate imported function prototypes to ae_bridge.h.
ae-bridge: Move main entry from SDL/main/android to ae-bridge.

The version in SDL/main is just a starting example for SDL clients.
We move our customized version into ae-bridge so that we don't have to
touch the one provided by SDL.  One less conflict when syncing with
upstream SDL.

I reverted the SDL_android_main.cpp to upstream SDL revision 4999 (on
the SDL 2.0 branch) which seems to be a pretty close match to where we
began customizing.  It's no longer compiled into our app, so it doesn't
really matter what I changed it to (if at all), but this should make
synchronizing with upstream SDL a tad smoother and the git history a
little clearer.
ae-bridge: Move imported functions from SDL/core/android to ae-bridge.
ae-bridge: Move exported functions from front-end to ae-bridge.
ae-bridge: Minor simplifications, encapsulation.

Local jni environment variable renamed mEnv => env to avoid confusion
with member/global variables.
ae-bridge: Remove obsolete functions (vibrate, showtoast).

ShowToast no longer used.  Vibrate superseded by Rumble in
input-android plugin.
cleanup: Update CoreInterfaceNative to match new ae-bridge implementation.
ae-bridge/front: Renamed some JNI methods for clarity, consistency.
ae-bridge: Fix a bug I just created.

Bug introduced in commit
3949f485c7269a26391d083b3f6fe27506201630
Merge branch 'master' into littleguy77/ae-bridge

Conflicts:
	jni/gles2rice/src/OGLGraphicsContext.cpp
	jni/gles2rice/src/OGLRender.cpp
	jni/gles2rice/src/Video.cpp
ae-bridge: Revert exported SDL funcs and wrap functions in ae-bridge.

Rather than modifying the names of the SDL functions to match the java
package name, we just write wrapper functions that call the original
exported functions.  Again, just minimize the diff with SDL upstream.
This also makes the transition to SDL 2 a bit cleaner.

Also, I decided not to wrap onNativeAccel, since we don't use it.
ae-bridge: Rename init -> sdlInit for consistency with others.

All SDL-state-related exports are prefixed with 'sdl'.
All mupen64plus-state-related exports are prefixed with 'emu'.
Merge branch 'littleguy77/ae-bridge'

Conflicts:
	jni/gles2rice/src/OGLGraphicsContext.cpp
	jni/gles2rice/src/Video.cpp
	src/paulscode/android/mupen64plusae/CoreInterfaceNative.java
	src/paulscode/android/mupen64plusae/GameLifecycleHandler.java

Hidden logical conflicts, manually fixed:
        src/paulscode/android/mupen64plusae/PlayMenuActivity.java