plugins: compositor: implement screencast recorder interface

Code comes from https://github.com/nemomobile/lipstick/pull/221

Signed-off-by: Simon Busch <morphis@gravedo.de>
tools: recorder: add simple screencast recorder utility

Taken from https://github.com/nemomobile/lipstick-recorder

Signed-off-by: Simon Busch <morphis@gravedo.de>
Add LGPL-2.1 license text

Signed-off-by: Simon Busch <morphis@gravedo.de>
Bump component version to 0.2.0

Signed-off-by: Simon Busch <morphis@gravedo.de>
Remove comment about old test_webapp utility

Signed-off-by: Simon Busch <morphis@gravedo.de>
plugins: compositor: add recording indicator for shell implementations

Signed-off-by: Simon Busch <morphis@gravedo.de>
tools: recorder: hardcode XDG_RUNTIME_DIR until we have proper session management

Signed-off-by: Simon Busch <morphis@gravedo.de>