dlgtrackinfo.ui - using bold words in non-editable fields
a better word to change cover action - using "change" instead of "edit"
a better word to "remove cover" action - using "unset" instead of "remove"
dlgtrackinfo.ui - increasing sizeHint height of vertical spacer - all fields must be always on top
dlgtrackinfo - change window title, using "Artist - Title" instead of "Title"
dlgtrackinfo.ui - Drawing all fields with fixed height (25px)
Unset Cover Action - changing the cover location to default_cover instead of use coverId=-1
It avoids Mixxx to keep searching for a cover (after unset)