flagprocessors: writetransform function take side data as parameter (API)
If we want some flag processors to be able to store sidedata it needs to be
actually fed that data.
Differential Revision: https://phab.mercurial-scm.org/D6816
flagprocessors: add a `sidedata` parameters to _processflagswrite
To read sidedata using flagprocessors, we need flag processors to store them. So
we pass this information to the flag processing layer.
Differential Revision: https://phab.mercurial-scm.org/D6815
revlog: add a `sidedata` parameters to addrevision
If we want to eventually store sidedata we need to be able to pass them along.
Differential Revision: https://phab.mercurial-scm.org/D6814