Webdesign for edit area name

Added textbox and button for changing the name of an area. Left to fix
is the server side that must update the area name.
Server-side code for edit area name

Added server side code for editing area name. A new area with the new
name gets  created, followed by a move of all items from the old area
when the user triggers rename. Finally, the old area gets deleted.
Update of "rename area"-change after review

* Replaced <br> tags with styles
* Made sure that all characters that could be dangerous for URLs are
forbidden in the area names. This is characters such as . ; % #
Fixed more invalid characters

Now also removing backslashes and euro signs in area names.
Merge pull request #51 from fredrikpersson/version

Allow administrators to edit area name