githelp: vendor Facebook authored extension
This commit vendors the Facebook-authored "githelp" extension. This
extension provides a "githelp" command that can be used to try to
convert a `git` command to its Mercurial equivalent. This functionality
is useful for Git users learning Mercurial.
The extension was copied from the
repository at revision 32ceeccb832c433b36e9af8196814b8e5a526775. The
following modifications were made:
* The "testedwith" value has been changed to match core's conventions.
* Support for a custom footer has been removed, as it is Facebook
specific. The feature is useful. But the implementation wasn't
appropriate for core.
* A test referencing "tweakdefaults" has been removed.
* Imports changed to match Mercurial's style convention.
* Double newlines in test removed.
* Pager activation changed to ui.pager().
* Initial line of githelp.py changed to add description of file.
The removal of the custom footer code was the only significant
source change. The rest were mostly cosmetic.
There are still some Facebook-isms in the extension. I'll address
these as follow-ups.
.. feature:: githelp extension
The "githelp" extension provides the ``hg githelp`` command. This
command attempts to convert a ``git`` command to its Mercurial
equivalent. The extension can be useful to Git users new to
Mercurial.
Differential Revision: https://phab.mercurial-scm.org/D1722
Our full contribution guidelines are in our wiki, please see:
https://www.mercurial-scm.org/wiki/ContributingChanges
If you just want a checklist to follow, you can go straight to
https://www.mercurial-scm.org/wiki/ContributingChanges#Submission_checklist
If you can't run the entire testsuite for some reason (it can be
difficult on Windows), please at least run `contrib/check-code.py` on
any files you've modified and run `python contrib/check-commit` on any
commits you've made (for example, `python contrib/check-commit
273ce12ad8f1` will report some style violations on a very old commit).