Use bootstrap-daterangepicker instead of bootstrap-datetimepicker and add Time filter support

WForms2 compatibility – resumed

Set cover-package for running tests

fix greater/smaller filters for pymongo

Fix incorrect usage of NotImplemented constant

`NotImplemented` is a constant singleton used in rich comparison
overloading. It is not callable, and is not an exception.
`NotImplementedError` is a built in exception.

WTForms 2 compatibility

Replaced deprecated TextField with StringField

Typo fix in form_rules.rst

IE8 filters compatibility

Use child icon in menu macro

Standardise Examples

filter never worked, because value is passed as string and mongodb returns zero documents

Update Bootstrap info

See "New license" section of http://blog.getbootstrap.com/2014/01/30/bootstrap-3-1-0-released/
and https://github.com/twbs/bootstrap/blob/master/LICENSE

See http://getbootstrap.com/about/#brand