match: add 'include:' syntax...
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).
