improve datePicker on usermanger page
remove whitespaces
change to plus 100 years as opposed to hard coded date
Merge pull request #767 from CharlieMarshall/usermanager-datePicker

Imrpoves the datePicker on the add/edit userManager page
Remove datetimepicker.js since it's not used anymore
Fix interface selections on UPnP to show the customized descriptions entered by the user. While here, add an external interface selection knob. Fixes #3141

Conflicts:

	etc/inc/pkg-utils.inc