[Gtkradiant] Compile errors on Ubuntu 11.10

[Nerius Landys]

A problem was reported by a guy named "neil".  I confirmed his problem
by trying out compiling GtkRadiant on Ubuntu Desktop 11.10 i386 (32
bit).

The problem is "undefined reference errors".  I don't have an exact
output for the problem at the moment, but I could possibly reproduce
the problem tonight and attach the output.

neil fixed the problem himself.  He says, he edited
SConscript.radiant, SConscript.module, and SConscript.q3map2, where he
replaced:

  env = Environment()

with:

  LINKFLAGS='-Wl,--no-as-needed'
  env = Environment(LINKFLAGS=LINKFLAGS)

I'm not too good at SCons, and I'm not sure what these changes mean.

TTimo says he may get around to looking into this problem and
committing a change (since he's fairly familiar with SCons).

Neil (who is bcc'ed), if you want to join the developer discussion
info is here: http://icculus.org/mailman/listinfo/gtkradiant