gc_math: Define macros for asserting vec4 equality

Define the following macros:
    assert_float_equal
    assert_vec4_equal
    assert_vec4_homo_equal
gc_math: Add tests for rotations

Add tests:
    mat4_rotation_x_and_axis_angle_agree
    mat4_rotation_y_and_axis_angle_agree
    mat4_rotation_z_and_axis_angle_agree
gc_math: Add funcs mat4_print, vec4_print

These are useful for debugging.
gc_math: Remove unused print_matrix* functions
gc_math: Respect w coord in mat4_axis_angle()