outgoing: merge the code handling --graph with the main one
The --graph code had its own copy of the logic. With the previous reorganisation
of the code, we can now merge it with the main code, reducing fragile
complication.
As a side effect, `hg out --graph` now use the right return code when they are
nothing outgoing. This explain the change to output in
`tests/test-largefiles-misc.t`.
Differential Revision: https://phab.mercurial-scm.org/D10383
== Local
Ready.
Un and Deux
Eins und Zwei
One and Two
Eins und Zwei
Uno und Due
== Remote
Ready.
REQ: foo?one=Vo&two=Efvy
-> Vo!boe!Efvy
Un and Deux
REQ: bar?b=Fjot&a=[xfj
-> Fjot!voe![xfj
Eins und Zwei
REQ: batch?cmds=foo:one=Pof,two=Uxp;bar:b=Fjot,a=[xfj;bar:b=Vop,a=Evf
-> Pof!boe!Uxp;Fjot!voe![xfj;Vop!voe!Evf
One and Two
Eins und Zwei
Uno und Due