Remove references to indexPath

The cell shouldn’t know about its indexPath, if the indexPath is needed
in the delegate just use [tableView
indexPathForCell:(UITableViewCell*)cell].
Add image support for buttons.
Ignore user state.
Fix slippery panning.
Add minimum width for buttons.
Fix the cells partially opening when scrolling

Also, cleaned up the code in the pan gesture, much of it was
duplicating itself.
Merge branch 'markflowers-master' into flowers-integrate + Fix Merge Conflicts

- Also update some documentation.

Conflicts:
	DNSSwipeableCell/MasterViewController.m
	Library/DNSSwipeableCell.m
Update example font method.
Update documentation with defaults and finish switch statement
Remove previous fix for scroll slop
Update index path retrieval
Code cleanup and commenty things
Updated README.