there is an update on this:
you don`t need to grab the base archive anymore.
everything is in svn now.
but you have to compile the maps, too (this step will need a few hours to finish)
just call the compile.pl (need perl installed) by typing perl compile.pl (for windows - use active state - linux type only ./compile.pl) in base/maps.
this will call the qbsp3 and qrad3 command which can be found in src/tools
^^when they are not compiled right now, type make in this dir (for windows, you can grab them from the files section of our sourceforge.net project site - they are included in the tools-archive)