rhg: support "status FILE" This change adds a new [file] argument to rhg status, parses them as patterns, canonicalizes the paths, and constructs a new PatternMatcher to intersect with the existing matcher being passed to the status implementation. We also make filepatterns a public module so we can access the pattern-parsing functionality we need from commands/status.rs.

pub mod dirstate_map;
pub mod on_disk;
pub mod owning;
pub mod path_with_basename;
pub mod status;