library: holograph: add animation backend

This is actually a straight port over from here;
https://bitbucket.org/danielnadeau/holographlibrary/pull-request/46/add-pie-animate/diff

Allows us to simply animate our slices.

Signed-off-by: Blechd0se <alex.christ@hotmail.de>
statistics: add animation for the pie chart

Android "L" showed us animations could be use intelligently.
While loading the slices and the underlaying data we can simply
show a small animation.

Signed-off-by: Blechd0se <alex.christ@hotmail.de>