Adding support for frame-based animations. This is basically a frame renderer defined as follows:
- List of frames
     + A frame (TimedRenderer) is a wrapper for any other renderer. It also includes the duration
- Function to determine the sequence of frames
     + Two types are currently supported: linear (with loop/no loop variants) and random. Linear is default, if not specified.
Solving issues identified on revision
Merge branch 'master' of https://github.com/e-ucm/ead into renderer-frameanimation
Adding test for Frame Animation
Adding test for Frame Animation
Null issues solved.
Merge pull request #59 from jtorrente/renderer-frameanimation

Adding support for frame-based animations. This is basically a frame ren...