Remember sorting

A cookie is saved for 60 days to remember sorting when a user sorts the
backlog on something else than the default 'rank'.

fixes sonyxperiadev/BacklogTool#53
Bugfixes for sorting

Fix for editing items not possible when sorting on something else than
rank.

Also fixed a bug where sorting was possible after editing and saving an
item even though the list was sorted on something else than rank.

fixes sonyxperiadev/BacklogTool#53
Merge pull request #54 from fredrikpersson/ordercookie

Remember sorting
Footer with version number

A footer on each web page has been added and displays the version number
set in the pom.xml file.
Also made sure that every user's cache will be automatically refreshed
for the javascript and css files when the verison number is changed.

fixes sonyxperiadev/BacklogTool#32
Merge branch 'versionnumbering' of https://github.com/fredrikpersson/BacklogTool into versionnumbering