1.7.0-pre - Window drag lag & UI freeze fixes

Adds an option for switching between the custom and standard OSX titlebar.

In testing, the drag lag and UI freeze issues don't seem to be present when using the standard OSX titlebar, so testing and feedback would be welcome (radiant-player#480)

Titlebar can be changed in Preferences > Appearance > Use custom title bar

Radiant Player - changes between 1.5.0 and 14th December 2015

A collection of all new features/changes/fixes between the 1.5.0 release and 14th December 2015.

Full list of commits for this period can be seen here: radiant-player/radiant-player-mac@9624148...e6ca0d7

Cyan theme & dark theme fixes

Temp test build of the master branch including the new dark cyan theme. Up to date as of 30/11