Implemented ray trace from mouse position

- Added CheckCollisionRayBox() function.
- Updated and improved core 3d picking example (currently working as
expected).

- Fixed GetMouseRay() function.
- rlglUnproject() unused.

Fixed Android bug and added physic buttons inputs

- Fixed Android locking screen bug. OnDestroy() was called when locking
screen.
- Power button input must be handled by OS.
- AndroidManifest.xml is affected by configChanges="screenSize".
- Updated library header for android template.

- Added functions for detect when pressed, during down and when
released.
- Added defines for back, menu, volume up and down button numbers.

Two new functions added to save/load values as binary data:
- StorageSaveValue()
- StorageLoadValue()

Improved lighting and physac engine modules and added new example

New physics example to see AddForceAtPosition() behaviour applied to 5
rigidbodies.

- Improved physics calculations.
- Added AddForceAtPosition function (added to all enabled rigidbodies).
- Updated raylib header.

Corrected Android processing for some inputs (BACK button, VOLUME
buttons)
Redesigned Gestures system (some work still required)
SetEnabledGestures() - Only support desired gestures (requires some
review)

...to avoid .mem file creation

Added LoadBMFont() to load AngelCode fonts (.fnt)
Implemented LoadTTF() to load .ttf fonts (crappy packaging)

Useful to get a piece of text, could be used for text typing animations

Corrected some code details

Fixed Android compilation with 1.3 updates

- Added gestures module functions.
- Fixed screen tap detection.

- Fixed Android MakeFile adding gestures module.
- Fixed Android project template functions names.
- Updated compiled library and header.

New matrix location points, lighting and physics engine modules with examples

- Added new physics engine-module with four new data types: Physics,
Transform, Rigidbody and Collider. This library contains functions to
apply physics calculations to a position vector calculating collisions
automatically.

- Fixed some writing mistakes of lighting module.