user groups support

[Alexey M. <al...@hs...>]

ok, I've preliminarily implemented support for user groups both in
libcvsacl and in cvs binary itself.

When the CVSROOT/cvsgroup file exists, it specifies the CVS groups in
the following format:

   %devel: alice, bob, carol
   %mgmt: mike, nick
   %devel: dave, elisabeth

As you see, the group names could be specified several times: lists of
users will just be added up together: this is to get rid of too-long
lines in cvsgroup.

To edit that file, you simply 

	$ cvs co CVSROOT/
	$ echo cvsgroup >> checkoutlist
	$ cvs add checkoutlist cvsgroup
	$ vi cvsgroup
	$ cvs ci

When there is an error in the cvsgroup file, the users will get a
warning about that, but not a fatal error (sure, the ACLs after that
line will not be honoured).


Special '%ALL' group is not supported yet.


Everything is committed.   Enjoy,

--alexm