core: Support slashes as well in GetFileName & GetDirectoryPath

Noted in #634.

Fixes #634.

lerp for vector2 and float

Fixes path to rlgl.h in README.md

The link to rlgl in the README was broken, it previously pointed to a .c file which doesn't exist (anymore).

Add the remaining numeric keypad keys, and a few other missing ones

Add the plus and minus keys on both the main keyboard and keypad

When a batch reach its vertex limit, a draw call is issued and batch restarted for refilling but if the draw call was issued for vertex data accumulated inside rlPushMatrix/rlPopMatrix, draw call was issued before the rlPopMatrix, consequently modelview matrix was not properly recovered before the draw call... obviously, it only happened the following draw calls, not the first one...

Now it works ok but this system needs to reviewed, noticed and important frames drop when processing around 20 dynamic batch draw calls, it means filling MAX_QUADS_BATCH (8192) quads of data 20 times per frame, including data updating and sending for draw processing.

Doing some maths, it means:
Vertex data (float) -----> 8192 quads * 4 vertex * 3 comp * 4 byte = 393216 bytes
Texcoords data (float) -> 8192 quads * 4 vertex * 2 comp * 4 byte = 262144 bytes
Color data (uchar) -----> 8192 quads * 4 vertex * 4 comp * 1 byte = 131072 bytes

Thats a total of 786432 bytes (0.75MB) sent to GPU 20 times per frame for processing... I'm testing in an Intel HD Graphics integrated, I imagine is too much data to be sent and and it causes stalls, so the frames drop...

Corrected memory leak!

Raymath dllexport fix

- Using raylib.h as reference, added define checks for BUILD_LIBTYPE_SHARED and USE_LIBTYPE_SHARED.

- Added check for dllexport to compile if _WIN32 defined.
- If not defined then use the original RMDEF.

- Added __declspec(dllexport) to RMDEF in raymath.h. This allows them to be accessed when importing from raylib.dll.

Added Sublime Text 3 project template

- Added Sublime Text project file.
- Added Sublime Text build system.

Shapes: Simplifies CheckCollisionRecs

Games: Fixes bugs in Snake

By comparing the edges of the rectangles relative to each other we can
determine if they intersect or not.

CheckCollisionRecs() returns true on edge-collision what means that the
snake eats the fruit when colliding with it but also when sliding by one
unit above or below the fruit.

If the initial fruit position collides with the snake's body a new
position for the fruit is generated but without adding the grid offset.

Update mini_al to 0.8.5.

This should improve the Raspberry Pi experience.

[Feature Request] 9-patch drawing function

See raylib/examples/textures/textures_image_9patch.c for how to use `DrawTextureNPatch` function.

Corrected issue with sound playing (pop sound at the end)

Just reviewing for a possible adaptation of AnimatedModel to default raylib Model...

Fix compiler warnings

Added support form vertical and horizontal 3-patches.
Corrected the distortion caused when destRec size is smaller than 4x4. Now even 1x10 or 0x0 sizes are drawn correctly.

Added support form vertical and horizontal 3-patches.
Corrected the distortion caused when destRec size is smaller than 4x4. Now even 1x10 or 0x0 sizes are drawn correctly.

[physac] Fix Physac examples to be run without creating new thread

Added DrawNinePatch() function implementation.

Added NinePatch struc definition and function prototype.

fix problem when compiling with MSVC 2017, error C2177