revlog: make the index always return the same tuple
It is simpler to manage the diferrence in on disk format in the internal index
code itself and lets the rest of the code always handle the same object.
This will become even more important when the data we store will be entirely
different (for example the changelog does not need the "linkrev" field.
We start with item reading, we will deal with item writing in the next
changesets.
Differential Revision: https://phab.mercurial-scm.org/D10568
== 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