Allow activation of more than one presentation
Enabled deactivation of presentations
Chenged some more things in Presentation model
Improved documentation in presentation.go
Added timestamp to config
Removed active presentation from upload.html
Included Thumbs.db in .gitignore
Reworked the system of Actions and client updates
A lot of changes

The datepicker has been replaced by a nicer looking one with a better
API.

The planned activations system has been updated to also support deactivations.
Bumped the version
Added a migration function
Minified bootstrap-datepicker.min.js
Fixed a bug where config.Timestamp was not included in JSON
Fixed a day order bug in bootstrap-datepicker
Fixed some bugs in TimeConfigs
Update external JavaScript
Fixed some timezone issues with config
Removed beta from version