Added Appstream XML data. Needs to be reviewed
Fixed appstream.xml more fit to project. Changed description coming from 'debian/mixxx.sgml' and changed me from copyright to author also fixed correct email address
Changed 'Bulk BPM and beat detection.' to 'Beat and key detection' what should open to most people.
Changed '&#38; (HTML: &)' to and which I think correct
Every comma now have space after appearence
little debug + cleanup
const removal
Merge pull request #395 from demos/master

Enabling parsed svg for spinny + cleaning
Merge pull request #389 from illuusio/appstream-fix

Added Appstream XML data for better Gnome and KDE integration.
Deere skin: Fix missing foreground images on Spinny widget on Deck 3 and 4. Use only one image for all decks, we can later add different colored versions for each deck if there is demand.
Revert "Allow to show/hide Effects from the toolbar. Preserve the extra show/hide button in the Effect-rack to switch between simple/advanced effect chain view. Make Effect section invisible on initial skin load. Later changes by the user persist."

This reverts commit bf04d25461c9ce682f3680b7566197e4de762864.
Deere skin: Fix "Could not parse vertical size policy: "f," debug error
Deere skin: Fix "Could not parse horizontal size policy: " " debug error
Merge remote-tracking branch 'upstream/master' into deere_updates