Fix Warning for edgeSizeFromCornerRadius

This fixes the warning
UIImage+FlatUI.m:13:9: No previous prototype for function 'edgeSizeFromCornerRadius'
Merge pull request #65 from Hackmodford/patch-1

Fix Warning for edgeSizeFromCornerRadius
Update rake task descriptions
Always add cancel button to index 0
Set cancel button frame to always be in bottom position.
Merge pull request #66 from Grouper/alertview-index

Fix AlertView cancel button index and position