add thumbnail upload
fix bitmap index problem
Update dispersy pointer
Merge pull request #528 from NielsZeilemaker/update_dispersy

Update dispersy pointer
notify metadata
add check for thumbnail and metadata
polish upload thumbnail
Merge pull request #526 from LipuFei/metadata-thumb-dialog

add thumbnail upload dialog
Merge remote-tracking branch 'upstream/devel' into playtorrent

Conflicts:
	Tribler/Main/vwxGUI/list_details.py