Fix placeholder bug that remained hidden although it should has been shown. The following cases have been covered.
1. No tokens - enter text  and delete text
2. One token - delete token
Merge pull request #64 from mrvincenzo/master

Fix placeholder bug that remained hidden although it should has been shown
Clean up
fix for #61. No reason to shift focus to tokenField
Handle transparent navigation bar in ios7. Fixes #62
Merge pull request #65 from nagrao/ios7

fix for #61. No reason to shift focus to tokenField