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.

- New lighting engine module which contains new data types Light and
Material. These data types and functions facilitates making a basic 3D
iluminated program with a light and a model.

- Added lighting engine module example (currently included in raylib.h;
it might be compiled by separate and include lighting.h in game source C
file).

- Corrected some opengl defines control structures and added some TODO
to fix raylib-opengl 1.1 source build (note: now source can be compiled
without errors, but rlglReadPixels() won't work properly).

Note: most of functions of phong version 330 shader are not in v100
shaders, so I couldn't write a version 100 phong shader. These functions
are included from version 150.

- New model and view transformation matrix added, useful for shaders.
Modelview matrix not deleted to keep opengl 1.1 pipeline compatibility.

- New extra function added DrawModelWiresEx() to set a rotation and
scale transformations to a wire model drawing.

- Other writing and little audio.c bug fixed.

BeginDrawing() function with extended parameters

Mouse button values are inverted!

Updated functions:
Image GetTextureData(Texture2D texture);
void *rlglReadTexturePixels(Texture2D texture);

LoadTextureEx() - Simplified parameters
UpdateTexture() - Added, allows updating GPU texture data

Added Alpha Numeric Mapping For Develop Branch