gendoc: automatically create help for default extensions.
Adds a section in the hg.1 manpage and corresponding hg.1.html
file. Each extension is listed with its module docstring, followed by
the commands defined by that extendsion.
Creates help for extensions by extracting doc strings from the extension modules
and its commands.
$ hg init 1
$ echo '[ui]' >> 1/.hg/hgrc
$ echo 'timeout = 10' >> 1/.hg/hgrc
$ echo foo > 1/foo
$ hg --cwd 1 ci -A -m foo
adding foo
$ hg clone 1 2
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg clone 2 3
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo '[hooks]' >> 2/.hg/hgrc
$ echo 'changegroup.push = hg push -qf ../1' >> 2/.hg/hgrc
$ echo bar >> 3/foo
$ hg --cwd 3 ci -m bar
$ hg --cwd 3 push ../2
pushing to ../2
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files