match: add 'include:' syntax This allows the matcher to understand 'include:path/to/file' style rules. The files support the standard hgignore syntax and any rules read from the file are included in the matcher without regard to the files location in the repository (i.e. if the included file is in somedir/otherdir, all of it's rules will still apply to the entire repository).

match: add optional warn argument Occasionally the matcher will want to print warning messages instead of throwing exceptions (like if it encounters a bad syntax parameter when parsing files). Let's add an optional warn argument that can provide this. The next patch will actually use this argument.

match: add source to kindpats list Future patches will be adding the ability to recursively include pattern files in a match rule expression. Part of that behavior will require tracking which file each pattern came from so we can report errors correctly. Let's add a 'source' arg to the kindpats list to track this. Initially it will only be populated by listfile rules.

check-code: reintroduce str.format() ban for 3.x porting In their infinite wisdom, the Python maintainers stripped bytes of its % and format() methods for 3.x. They've now added % back to 3.5, but format() is still missing. Since we don't have any particular need for it, we should keep avoiding it.

util: drop the 'unpacker' helper It is not helping anything anymore.

MBTextWrapper: drop dedicated __init__ method It was only there as a compatibility layer with a version of Python which we do support anymore.