Merge pull request #2 from bjhomer/master

A bunch of changes
Merge pull request #3 from bjhomer/button-deleteBackward

Teach JSTokenButton to handle backspace.
Merge pull request #4 from bjhomer/layout-fixes

Layout fixes
(manually merging pull request from bjhomer) Don't modify the array of tokens while we're iterating it.
Merge pull request #5 from bjhomer/crash-fix

Don't modify the array of tokens while we're iterating it.
(Manually merging BJHomer's commits: Make the didAdd and didRemove delegate methods consistent, and Allow removing tokens by represented object.
fix method name which passed to respondsToSelector method.
set zero width space string on token add instead of relying on handler
Merge pull request #11 from vishl/master

Fix delete on iOS 6
Merge pull request #10 from hirakiuc/patch-fix-old-delegate-method-name

fix method name which passed to respondsToSelector method.
when add token to the field, add zero width space so that backspace will delete the text
Merge pull request #14 from siuying/delete-fix

Fixes problem adding or removing tokens in iOS 6