i18n: fix trailing '::' on translated messages

Reported by FUJIWARA Katsunori <foozy@lares.dti.ne.jp>.
merge default into stable for 2.9 code freeze
merge with i18n
Added tag 2.9-rc for changeset 8862469e16f9
Added signature for changeset 8862469e16f9
makefile: add $ to environment variables in help message
templater: selecting a style with no templates does not crash (issue4140)

Running `hg log --style compact` (or any other style) raised a traceback when
no template directory was there. Now there is a message:

Abort: style 'compact' not found
(available styles: no templates found, try `hg debuginstall` for more info)


There is no test because this would require to rename the template directory.
But this would influence other tests running in parallel. And when the test
would be aborted the wrong named directory would remain, especially a problem
when running with -l.
hgext: fix one typo in rebase
phase: properly compute ancestors of --rev on push (issue3786)

Now that discovery is working on unfiltered changeset, I had a good occasion to
look at that bug again. This let me realise that a trivial node vs rev
comparision was the cause of this two years old bugs…

Happy second birthday phases!
merge with stable
exchange: extract push function from localrepo

The localrepo class if far too big. Push and pull logic will be extracted and
reworked to better fit with the fact they now exchange more than plain changeset
bundle.

This changeset extract the push code. later changeset will slowly slice this
over 200 hundred lines and 8 indentation level function into smaller saner
brick.

The localrepo.push method is kept for now to limit impact on user code. But it
will be ultimately removed, now that the public supposed API is hold by peer.
push: introduce a pushoperation object

This object will hold all data and state gathered through the push. This will
allow us to split the long function into multiple small one. Smaller function
will be easier to maintains and wrap.  The idea is to blindly store all
information related to the push in this object so that each step and extension
can use them if necessary.

We start by putting the `repo` variable in the object. More migration in other
changeset.
push: ease access to current ui object

The `pushoperation.repo.ui` attribute is very commonly used. we offer a faster way
to access it directly through the push operation object.
push: move `remote` argument in the push object

One more step toward a more modular push function.
push: move `force` argument into the push object

One more step toward a more modular push function.
push: move `revs` argument into the push object

One more step toward a more modular push function.
push: move `newbranch` argument into the push object

One more step toward a more modular push function.
push: move bookmarks exchange in the exchange module

The bookmark exchange code was already extracted during a previous cycle. This
changesets moves the extracted function in this module. This function will read
and write data in the `pushoperation` object and It  is preferable to have all
core function collaborating through this object in the same place.

This changeset is pure code movement only. Code change for direct consumption of
the `pushoperation` object will come later.
merge with stable
Makefile: hg.pot depends on the scripts generating it

This is convenient when editing this scripts. And translators will get updated
translation files even if nothing else has changed.