Merge pull request #984 from rjruigrok/fixmute

Fix mute-button in mediaplayer
disable automatic thumbnail generation
update MetadataCommunity identifier
fix some pep8 problems in db_upgrader.py
skip metadata test
clean up thumbnails
fix typo
Merge pull request #981 from LipuFei/disable_thumbnails

Disable automatic thumbnail generation
Lower log level for tunnel most of the tunnel community.
Lower a couple of log entries that aren't errors.
Merge pull request #988 from whirm/lower_tunnel_loglevels

Lower log level for tunnel most of the tunnel community.
add profiler for TFTP
stop generating metadata
disable MetadataCommunity
Merge pull request #996 from LipuFei/some_fixes

Some fixes
Don't join until we fix the timeout stuff on select()
Raise the default loglevel of TunnelCommunity to ERROR.
Also Add a list of all the loggers in Tribler to logger.conf
Remove redundant TunnelCommunity prefix on log entries
Merge pull request #999 from whirm/drop_tunnelcommunity_logging_prefix

Remove redundant TunnelCommunity prefix on log entries
Merge pull request #997 from whirm/dont_join

Don't join until we fix the timeout stuff on select()