Reworked RunActivity startup to allow profiling to be done via a command-line switch.
Compass window changed to update the heading every frame to make it smooth.
Compass window now caches widths of text.
Popup windows screen texture resized when window resized.
git-svn-id: http://svn.uktrainsim.com/svn/openrails/trunk@243 a9f3cfff-6c41-7446-b0ca-052bd761e6eb