post-release version bump
Video plays by default (at startup).
Bugfix: video size was not properly set for many videos.
Major cleanup in MediaImpl
Support shmsrc (live source)

If the imported file is a socket path, we mark the media as "live". We
continuously poll for the socket path (in case e.g. it disappears / reappears).
As soon as the source socket patch exists, we connect a shmsrc ! gdpdepay
pipeline  (instead of a normal uridecodebin element for file-based media) and we
set the pipeline state to PLAYING (playAction button is not needed at the moment
for live sources, but we can change behaviour to only start the pipeline if
play is selected, like with normal file-based media)

In case of a GST_MESSAGE_ERROR, the polling function keeps looking for the
socket path until it exists again. The existing shmsrc pipeline is re-used
once the live source is transmitting again.

Tested with live source gst-launch-1.0:

gst-launch-1.0 uridecodebin uri=file:////opt/Videos/test.avi !  queue !
videoconvert ! video/x-raw, format="RGBA" ! gdppay ! shmsink
socket-path=/tmp/sock  shm-size=100000000

The live source was interrupted and restarted again, and the shmsrc in mapmap is
able to pick up the reappearing media stream.

Signed-off-by: Vasilis Liaskovitis <vliaskov@gmail.com>
Add .sock extension for live sources
Reorganized elements in window
fix fullscreen on gnome
Update read and write settings for new elements
Switch to paint tab when new paint added
Switch to mapping tab when mapping is added.
When mapping is changed, corresponding paint is changed
When paint is changed, unselect any mappings
Small fixes
Fix main splitter proportion
Main splitter gets all the extra width when window is stretched
New feature: menu option toggle sticky vertices
Fix: radius for dragging vertices. Drag shape with left click.
Feature: Select a shape with a click
Fix: Press Esc: Do not close output window