tests/test-check-pylint.t

revlog: move the details of revlog "v2" index inside revlog.utils.constants

the revlog module is quite large and this kind of format information would handy
for other module. So let us start to gather this information about the format in
a more appropriate place.

We update various reference to this information to use the new "source of truth"
in the process.

Differential Revision: https://phab.mercurial-scm.org/D10305

#require test-repo pylint hg10

Run pylint for known rules we care about.
-----------------------------------------

There should be no recorded failures; fix the codebase before introducing a
new check.

Current checks:
- W0102: no mutable default argument

  $ touch $TESTTMP/fakerc
  $ pylint --rcfile=$TESTTMP/fakerc --disable=all \
  >   --enable=W0102,C0321 \
  >   --reports=no \
  >   --ignore=thirdparty \
  >   mercurial hgdemandimport hgext hgext3rd | sed 's/\r$//'
  Using config file *fakerc (glob) (?)
   (?)
  ------------------------------------* (glob) (?)
  Your code has been rated at 10.00/10* (glob) (?)
   (?)