Serialization of the folder list in map manager
Add management of user defined local folders
Show custom map folders
Enhance TreeNodeFolder
As I guess (know) that Erwan and/or Gwendall will load /home/ in map catalog, folders are now loaded on user request limited on current node unfolding
remove dolphin preferencies file
javadoc
Merge pull request #534 from nicolas-f/feature/mapmanage-remotefolder

The user can now load any local folder in the MapManager.

Fixes #531.