revert: warn that subrepos cannot be reverted (tests added by mpm)

merge: expand environment variables and ~/ in tool.executable hgrc(5) already implies that this works, so we might as well support it. Another approach would be to implement this in util.findexe(): that would benefit other callers of findexe(), e.g. convert and anyone calling the user's editor. But findexe() is really implemented in both posix.py and windows.py, so this would make both of those modules depend on util.py: not good. So keep it narrow and only for merge tools.

minirst: improve test harness

minirst: add style flag to format

minirst: add basic HTML formatting support

graft: use status verbosity for reporting grafts

contrib: add a script to help diagnose raw output of the cmdserver

mq: eliminate explicit checks for file existence

mq: cleanup of lookup - handling of None is not relevant Patch specifications in mq is passed around as a string or None. None is generally used when no patch has been specified and there thus is nothing to lookup and the calling code should do something else. One code path did however pass None all the way to lookup. That case was handled in lookup, but there was really need for that, it was undocumented, and it used to cause trouble back when patches was specified as integers.

mq: fix corner cases for handling of patch 0 in qselect Most of the code paths in mq would always pass patch specifications as a string. Patches can be specified by their index, but one code path passed that (through pop) to lookup as an integer - all other code paths used a string. Unfortunately pop and lookup (like many other parts of mq) used the boolean value of the patch specification to see if it was None, and they would thus incorrectly handle patch 0 as None. This patch makes the code comply with the actual internal duck typing of patch specifications: patch indices must be encoded as strings. The (now) unused code for partial and thus incorrect handling of indices as integers is removed.