libanim 2.0

Changes

There was never an official release 1.0, the development versions of libanim which were "leading" to 1.0 were hosted on sourceforge many years ago. There are tons of fixes since then, but the main differences are:

• switched the internal math library from libvmath to cgmath.
• dropped all dependencies to the math library from the API, making it use only basic C types instead.
• moved the special quaternion interpolation from 4 tracks (XYZW) routine, from the high level animation node interface, to a new anm_get_quat function in the low level track API, to make the low level API more useful in its own.