bin: disable docbook if disabling docs in pitivi-git
bin: Do not change directory if sourced or launching a command

+Rework the way we set PS1
Clarify a bit the comments
Remove unused variable
Set MODULES_CORE in a single place
Show info about up to date packages
Always build local pygobject and gobject-introspection
Calm down test_system_gnome
Add back missing Timeline.purgeObject
Add some missing imports in timeline.py
Use the proper timeline
Start the alignment when the button is pressed
previewers: Avoid blocking the UI when generating clip thumbnails

Put thumb generation in a low-priority idle GLib mainloop callback
previewers: Periodically save clip thumbnails

This improves perceived performance by saving "work in progress" thumbnailing.
Otherwise, long clips might never have a saved thumbnail cache.
previewers: Prevent the clip thumbnailer from choking on invalid URIs

If for some reason (ex: a dodgy project file formatter) we get URIs with spaces
in them, Gst.parse_launch will fail because it will see them as arguments.
Rendering: port to 1.0.

- Remove audio depth as it doesn't exist anymore
- Rename other caps.
- Use RENDER instead of SMART_RENDER as it's broken.
l10n: Update Japanese translation
Updated Czech translation
dogtail tests: Fix the media library test to be able to "Select unused clips"

This requires GTK+ 3.8 or newer to work, as GTK entry widgets' clickable icons
were not accessible to AT-SPI in earlier versions (bug #686347).
Updated Slovenian translation