Teacher events module management web interface.

Altered the existing teacher events module to be able to add and remove teacher training and interview timeslots. The name and friendly name are set automatically with a nice date format.
Moved the add form to the top of the page.
Teacher event nodes use integers and event type is properly set now.

This is in the teacher events module.
Merge pull request #521 from uakfdotb/issue27

Teacher events module management web interface.