POP->pop to reflect filesystem naming

Fixes #78
Merge pull request #139 from toulouse/master

POP->pop to reflect filesystem naming
Added support for animating edge insets with POPBasicAnimation
Basic animation supports UIEdgeInsets value type
Merge pull request #145 from sugarmo/uiedgeinsets-in-basic-animation

Basic animation supports UIEdgeInsets value type
Merge pull request #142 from ianolito/fix-edge-insets

Fixed support of edge insets with POPBasicAnimation
Removes duplicate symbol
Merge pull request #149 from inf0rmer/patch-1

Removes duplicate symbol