merge workspace into freeplane/master

-initial version of the new workspace as used for docear
missing adjustments and refactoring
make workspace shortcuts mac os compatible
branch cleaning
added debug info
changed debug info
merge with "freeplane/master"
bugfix for "new project folder was not created"
some code cleaning
fixed a problem with the new action enable method and workspace action
missing docear look&feel routine in FrameController
changed controller exec handling

-added IControllerExecuteExtension
Added view refresh with restored expanded node state
Add space in Recent Files List to improve readability
removed final modifier to make the root node inheritable
modification to allow replacement of menu actions
changed DefaultWorkspaceTreeModel to support nodes in root other than projects
fixed Exception when refreshing node expanded state on project-refresh
changed return type to generic for project.getExtension
modified project relative path handling for windows

-also: exception handling for expand state handling