debugcommands: use repo[None].walk instead of repo.walk

cmdutil: use repo[None].walk instead of repo.walk

largefiles: use repo[None].walk instead of repo.walk

parsers: add version to help detect breaking binary changes

osutil: add version to help detect breaking binary changes See the previous patch for why.

mpatch: add version to help detect breaking binary changes

diffhelpers: add version to help detect breaking binary changes

base85: add version to help detect breaking binary changes

bdiff: add version to help detect breaking binary changes Previously, we have no way to detect if a compiled .so file could be used or not, and blindly load it if it exists. Usually we carefully maintain compatibility of .so and fallback to pure code gracefully. But if we stick to the rules, certain nice changes will be impossible to make in a clean way. This patch adds a "version" constant to the module so we can detect inconsistency and take appropriate actions (warn, abort, fallback to pure, run make automatically) in module loader.

obsmarker: add an experimental flag controlling "operation" recording It seems better to introduce the experiment behind a flag for now as there are multiple concerns around the feature: * Storing operation increase the size of obsolescence markers significantly (+10-20%). * It performs poorly when exchanging markers (cannot combine command names, command name might be unknown remotely, etc)

run-tests: remove references to Python 2.6 These are the obvious ones. There is tons of code in this file implementing features from unittest that weren't present in Python 2.6. But that's for other patches.

dirstate: mark {begin,end}parentchange as deprecated (API)

merge: migrate to context manager for changing dirstate parents

localrepo: migrate to context manager for changing dirstate parents

context: migrate to context manager for changing dirstate parents

rebase: migrate to context manager for changing dirstate parents

mq: migrate to context manager for changing dirstate parents

dirstate: introduce new context manager for marking dirstate parent changes

contrib: make editmergeps able to work with notepad++ Notepad++ has a different FIRSTLINE argument, so needs special handling.

contrib: make editmergeps able to work with Windows GUI editors Using Start-Process -Wait makes it wait until the process finishes, which is necesssary for Windows GUI applications. My short testing also demonstrated that it does not hurt with command line vim.

extensions: show deprecation warning for the use of cmdutil.command Since this is a fundamental API for extensions, we set 1-year period until actually removing it.

extensions: prohibit registration of command without using @command (API) Detect the problem earlier for better error indication. I'm tired of teaching users that the mq extension is not guilty but the third-party extension is. https://bitbucket.org/tortoisehg/thg/issues?q=%27norepo%27

extensions: optionally print hint on import failure Test will be added by the next patch.

error: add hint to ProgrammingError As the hint isn't shown by the default exception handler, we need to print it manually. I've copied the "** " style from _exceptionwarning().