server: move service table and factory from commandserver
This is necessary to solve future dependency cycle between commandserver.py
and chgserver.py.
'cmd' prefix is added to table and function names to avoid conflicts with
hgweb.
$ hg init
$ touch a
$ unset HGUSER
$ echo "[ui]" >> .hg/hgrc
$ echo "username= foo" >> .hg/hgrc
$ echo " bar1" >> .hg/hgrc
$ hg ci -Am m
adding a
abort: username 'foo\nbar1' contains a newline
[255]
$ rm .hg/hgrc
$ HGUSER=`(echo foo; echo bar2)` hg ci -Am m
abort: username 'foo\nbar2' contains a newline
[255]
$ hg ci -Am m -u "`(echo foo; echo bar3)`"
transaction abort!
rollback completed
abort: username 'foo\nbar3' contains a newline!
[255]