More informative error message

From: Alexey Syomichev (asyomichev_at_[hidden])
Date: 2005-04-18 21:05:35

I've noticed that the "Duplicate name of actual target" error never 
shows the location in the "created from" field.
Having that information would make debugging of duplicate target issues 
much easier.
Changing [ $(cmt1).location ] to [ $(cmt1).full-name ] in the rule 
"register-actual-name" (virtual-target.jam:857) seems to help (same 
applies to [ $(cmt2).location ] at the line 859)
Line numbers are for the head CVS version.
Thanks,
--Alexey