Release 0.39

* fixed: jQuery Datepicker missed some Icons in kitEvent backend.
* fixed: on add-on updates the kitEvent.xml overwrites already existing
settings
* removed: no longer needed template /backend/DE/config.dwoo
* changed: kitEvent no longer need the kitTools
* changed: class.frontend.php passes calls from DropletsExtension to
avoid
double form submissions
* refactoring of the SQL usage in the class.backend.php
* refactoring of the SQL usage in the class.calendar.php
* refactoring of the SQL usage in the class.frontend.php
* refactoring of the SQL usage in the droplet.extension.php
* updated precheck.php
* removed no longer used class.event.php
* updated initialize.php
* fixed: uninstall does not remove the droplet kit_monthly_calendar
* changed: kitEvent is now direct to KeepInTouch and uses
class.interface.php
* changed: field item_desc_link from VARCHAR to TEXT
* complete rework and redesign of the backend - new look and feel
* added: filter method for the droplet kit_event