* use html5 email validation
* remove static cache seed, for compatibility with non default (file based) caches
* added caching ConfigurationService, removed use of doctrine result cache
* simplify configuration API
* do not close modal if form is dirty
* deprecated TimesheetConfiguration
* inject timezone in form types
* cleanup usage of UserDateTimeFactory
* allow to configure increment steps for minutes
* use 15 minutes step for datetimepicker in project edit form
* use rounding rules for increments in minute select for begin and end
* allow duration in multi user and admin timesheet forms
* make dropdown values configurable
