Import libdash project
Point libquvi-scripts submodule to new fork
Update libquvi-scripts for youtube MPEG-DASH
Avoid potential unneeded string copy
Minor cosmetics
Initialize some class fields with declaration
Add a few comments
Add an extra failsafe assert()
Request best quality, accept only http streams
Request content type from libquvi
Refactor in preparation for MPEG-DASH backend
Basic MPEG-DASH support