Fix reference name for css file
Update html elements and classes for bootstrap 3

Honestly, this is a little bit trial and error and it is still
misbehaving for the left and right arrows in the pop up but it is at
least formatting correctly and popping up.
Update datetimepicker js

To fix the bug where the left and right arrows at the top of the popup
are behaving incorrectly. They're meant to changes dates at the level
you're at but instead they take up down a level and out the bottom.
Merge branch 'name'