added Bootstrap 3 support and some options

Now it can add the button before the input, create button and input container when class are set, and can create Bootstrap input group.
some bugs fixed
Merge branch 'master' of https://github.com/Aharito/bootstrap-filestyle
Merge branch 'master' of https://github.com/markusslima/bootstrap-filestyle
Merge branch 'patch-1' of https://github.com/egea1981/bootstrap-filestyle
Merge branch 'master' of https://github.com/markusslima/bootstrap-filestyle
Add new version
Remove class icon bootstrap 3