Add camera.h
Add camera.h to CMakeLists.txt
camera: fix missing comment end
vec3: normalize, add, subtract, mult, divide, dot_angle, cross_angle functions
vec3: formatting fixes
vec2: added basic functions

functions include:
add
subtract
mult,
normalize,
divide,
dot_angle,
cross_angle
mat4: added basic functions

functions include:
add,
subtract,
multiplyf,
multiply
camera: camera2d and camera3d
camera2d: fix vec2 typo
texture2d: incomplete load and destroy implementations
Remove camera2d, rename camera3d back to camera, remove texture, update CMakeLists
Merge remote-tracking branch 'jgcoded/master' into develop

Conflicts:
	engine/CMakeLists.txt
math/vec2: Fix use of == with float operands