convert to Unix line endings
don't display headers when player panel is invisible
StyleCop
More style fixes.

Also fixes bogus recursive storage of OnGameStart
when a player is disconnected from the server.
Fix Map.GetSpawnPoints to return CPos.
Introduce MapCache and MapPreview for improved UI map previews.
Simplify the replay browser code.
Simplify the map chooser code.
Add data support to Download.
Simplify the server browser code.
Support custom map previews.

Add map.png to the map archive.
Update changelog.
Fix editor compilation.
Merge pull request #4878 from pchote/mapcache

Reorganize map management and preview generation