Merge pull request #533 from sealemar/master

A proposal to fix https://github.com/mrjoes/flask-admin/issues/532
Remove case sensitivity for column types (columns can be DATE)
Merge pull request #537 from pawl/master

Remove case sensitivity for converter column types
Improved consistancy

Lol not really i changed one line, that was distracting :)
Fixes #543: Import of wtforms _unset_value needs to change to unset_value
Force wtforms dependency version
Merge pull request #540 from psykzz/patch-1

Improved consistancy
Merge pull request #544 from Jaza/master

Fixes #543: Import of wtforms _unset_value needs to change to unset_value
Update travis.txt
Change bool_formatter() to be backward compatible with bootstrap2
Merge pull request #545 from xelez/master

Change bool_formatter() to be backward compatible with bootstrap2
Add widget_format field to DateTimeField to allow modifying datetime format from form_widget_args
fix spacing issue with previous commit
change __all__ to include DateTimeField
add comments to new DateTimeField
attempt to fix "Not a valid datetime value" error
add "format" parameter for string to date formatting
add formats back to __init__
remove "formats"
Merge pull request #549 from pawl/master

Allow Changing DateTimeField's date-format using form_args