This changes the remux dialog to support a collection of input/output
pairs, presented as a QTableView. Standard Qt icons are used to
indicate the state of each entry during a remux operation. Drag/drop
support is added to populate the list quickly. Both Dark and Rachni
themes are updated to make QTableView look reasonable.
Relevant text is added in the localization files.
Closesobsproject/obs-studio#1153
797b3dc121