Don't reveal playertoolbar when space is pressed.
mrpis: don't crash if some field cannot be found
mpris: don't crash if some field is missing and check other options if possible

https://bugzilla.gnome.org/show_bug.cgi?id=726721
potfiles: add mpris.py
mpris: skip all the exception when fetching track info

https://bugzilla.gnome.org/show_bug.cgi?id=726721
query: Use double quotes for url in get_song_with_url

Single quotes are not escaped in URIs, which causes syntax errors in the query if
the URI has single quotes. Use double quotes instead.
player: mpris: skip all the exception when getting artist
Implement a simple logging for the application
Use a logger for all modules
Trap OSTree errors when adding sources

https://bugzilla.gnome.org/show_bug.cgi?id=727444
log: add some debugs to grilo.py
Don't change view type after setting up the view
playlists: Don't crash when all items are removed

Since TotemPlParser cannot save empty playlists, insert a dummy item if all
items are removed in a playlist.
view: Set album title as Unknown Album if empty in Playlists view
Remove README.md
Select button should be sensitive only if playlist count is greater than 0.
clear playlist model before deleting the playlist.
grilo: remove duplicate logging
log: extensive logging
pep8: make pyflakes and pep8 happy