minor code cleanup
EHO-425 customer dropdown is not updated when a project is selected
EHO-425 dropdownchoice with support for optgroup
replaced getCustomers(true) with getActiveCustomers()
EHO-425 can't mix $ with \"
replaced getProjects(true) with getActiveProjects(). Passing booleans as arguments should be forbidden..
hail to junit tests...
EHO-425 project model is grouped on customer and then sorted on project name
EHO-425 groupable dropdown WIP
EHO-425 editing assignment -> when customer filter change the project choices are updated properly
EHO-425 default i18n strings added for "show all projects" filter
EHO-425 merged edit and create assignment panel
EHO-425 changed sort to first customer code, then project code instead of name