look over for errors

Reviewed vertex type variables

- Added function WorldToScreen(...).
- Added world to screen example.
- Review GetMouseRay() comment.
- Removed deprecated lighting functions from raylib header.

Simplified for the user (more intuitive and clear)
Removed lighting module dependency

... transparent elements

It seems that now works. Tested all free camera features with some
directions and positions and no unexpected behaviours detected. I don't
know if those lines are really indispensable.

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

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

- 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 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)

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

- 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);