Theme selection

Added menu items to select themes.
Added custom themes Red & Blue, stored in .thm files.
Added new lines in LanguageRepository.
Restart warning for language, fixed DB
Fixed a problem with DBHandler
rightclick popup is visible
Added weekday, date and time to titelPanel
Merge branch 'Sven'
Merge branch 'Kim5'
Merge remote-tracking branch 'origin/master' into Sercan