ixing a big problem on Windows platforms that has to do with copying over

ixing a big problem on	Windows	platforms that has to do with copying over
game packs to the game install directory.  Before this patch, users of
Radiant	weren't	able to	start Radiant without doing some manual	copying	of
game pack files over by hand (and	I'm sure nobody	figured	that out).
The problem is in radiant/missing.cpp. 	CopyTree() didn't correctly recursively
copy directories because of a problem in FindFiles::FindFiles() on Windows.

git-svn-id: svn://svn.icculus.org/gtkradiant/GtkRadiant/trunk@346 8a3a26a2-13c4-0310-b231-cf6edde360e5