branching: merge with stable

topic: improve UX by using pager only when we should Before this patch we were using pager in every case of topic command, either it is setting up a new topic or clearing the active topic. After this patch it will not use pager in following commands: $ hg topic [TOPIC] -r [rev] $ hg topic --clear

evolvecmd: _possibledestination() skip visiting empty parent I see that even in the case when "parent == -1" we are visiting that also and find succsets for that and in last -1 is being added in the set of possible destination. Why not skip that?

pick: `hg help` was not showing the full cmd desc of `pick` after running command `hg help` it was not including the second line of command description. I guess it picks the firstline only. So I moved that part in first line of cmd description.

test-compat: merge mercurial-4.4 into mercurial-4.3

test-compat: merge mercurial-4.5 into mercurial-4.4

test-compat: merge mercurial-4.6 into mercurial-4.5

test-compat: merge mercurial-4.7 into mercurial-4.6

test-compat: merge stable into mercurial-4.7

compat: fix fixedcopytracing compatibility with mercurial 4.8 and narrow Mercurial 4.8 version of _fullcopytracing includes some new narrow code. As https://phab.mercurial-scm.org/D3896 has not yet landed, update fixedcopytracing behind a version detection condition. This was spotted by Augie Fackler.