Small fix for menu background
Loop main menu video when it's finished playing
Fix several edit boxes not receiving mouse input
Merge DialInfo objects by subrecord instead of overwriting the object

Fixes #1360
Fix unhandled edge case in TradeItemModel with items that are able to stack, but are not currently stacked (e.g. after repairing a damaged item)

Fixes #1368
Make trade balance label editable
Make trade disposition changes temporary again, as in vanilla
Fix trade exploit

Using the Max Sale button it was possible to "invert" the buying/selling state.
Fix errors due to BaseWhite material being removed
When dialogue goodbye is forced, allow using either the red link or the goodbye button

Fixes #1373
Addition to 7c9c0830a96: don't create useless BaseWhite clones
Merge remote-tracking branch 'scrawl/master'