Remove qt5 dependency and old code

Signed-off-by: Simon Busch <morphis@gravedo.de>
Completely new implementation based on the Ubuntu mediascanner2

The whole code is now completely based on the amazing mediascanner2 project from the
Ubuntu guys (see https://launchpad.net/mediascanner2). The only thing which is changed is
at the moment the MediaStore implementation. It will be extended to store everything
within the db8 database.

Signed-off-by: Simon Busch <morphis@gravedo.de>
Add system integration part

* audio/video objects will be already created within the db8 database whe they get
  successfully discovered
* by default indexing /media/internal but configurable through configuration file

Signed-off-by: Simon Busch <morphis@gravedo.de>
Correctly add/remove files when directories are deleted or moved

Signed-off-by: Simon Busch <morphis@gravedo.de>
Remove concept of mount volumes and just one single root directory

Signed-off-by: Simon Busch <morphis@gravedo.de>
Also discover image and misc files

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