Big batch of changes, check description:

- Camera system moved to a separate module [camera.c]
- WIP: Added customization functions for camera controls
- Added custom shaders support on batch drawing
- Complete redesign of textures module to support multiple texture
formats (compressed and uncompressed)

examples/resources/shaders/custom.vs

@@ -0,0 +1,16 @@
+#version 330
+
+attribute vec3 vertexPosition;
+attribute vec2 vertexTexCoord;
+attribute vec3 vertexNormal;
+
+uniform mat4 projectionMatrix;
+uniform mat4 modelviewMatrix;
+
+varying vec2 fragTexCoord;
+
+void main()
+{
+    fragTexCoord = vertexTexCoord;
+    gl_Position = projectionMatrix*modelviewMatrix*vec4(vertexPosition, 1.0);
+}