Merge remote-tracking branch 'upstream/develop' into issue#385
Changed layout of pdfs.
Implemented TableBuilder in PDFHandler to replace the overloaded
fillTableWithContent...-methods.
Added method to get the EndDate of a term
Added first version ofcreation of first and second dunning. 
	Still very buggy.
Merge remote-tracking branch 'upstream/develop' into issue#385
Merge remote-tracking branch 'upstream/develop' into issue#385
Fixed bug where buttons were enabled without a selected row in the table
Implemented automatic creation of dunnings.
Changed Notification to using the eventBus
Merge pull request #437 from henningmu/live_search_sms

Filtering of students is now working for lending view
Merge pull request #439 from Junkern/issue#385

Issue#385
Merge pull request #442 from Junkern/issue#399

Changed Notification to using the eventBus
Changed method call 'lendingList' to method call 'returnList' in
ReturnView.
Refactored PDFHandler.
Replaced old method calls by new one (using TableBuilder)
Refactored PDF classes.
Set <Ok> as default Button
Merge pull request #443 from B3nRa/issue#425

Changed method call 'lendingList' to method call 'returnList' in
Merge pull request #444 from B3nRa/pdf

Refactoring of PDF classes and design changes of PDFs
Merge pull request #445 from jidel/confirm_default_button

Set <Ok> as default Button in ConfirmDialog