Improved workspace
Improved workspace

* 'Current Vistrails'/'My Vistrails' sections
* Context menu for pipelines - open/new tab/new window
* (latest) pipeline entry

gui/collection/workspace.py:
- QBrowserWidgetItem:
Use class of self for children
Stretch icon to fit 16*16
- QVistrailListItem.open_workflow: *new
- QVistrailListItem.open_workflow_in_new_tab: *new
- QVistrailListItem.open_workflow_in_new_window: *new
- QVistrailListLatestItem: *new - represents the latest pipeline
- QVistrailListLatestItem.open_workflow: *new
- QVistrailListLatestItem.open_workflow_in_new_tab: *new
- QVistrailListLatestItem.open_workflow_in_new_window: *new
- QVistrailList:
openFilesItem name changed to 'Current Vistrails'
recentFilesItem renamed to closedFilesItem
closedFilesItem name changed to 'My Vistrails'
- QVistrailList.contextMenuEvent: add menu for open pipelines

celiafish/VisTrails,celiafish/VisTrails,VisTrails/VisTrails,hjanime/VisTrails,Nikea/VisTrails,VisTrails/VisTrails,VisTrails/VisTrails,VisTrails/VisTrails,minesense/VisTrails,Nikea/VisTrails,celiafish/VisTrails,Nikea/VisTrails,minesense/VisTrails,celiafish/VisTrails,minesense/VisTrails,VisTrails/VisTrails,minesense/VisTrails,Nikea/VisTrails,hjanime/VisTrails,hjanime/VisTrails,hjanime/VisTrails,hjanime/VisTrails,minesense/VisTrails