rhg: Add support for ui.ignore and ui.ignore.* config
This fixes some but not all failures in `tests/test-hgignore.t` when running
with `rhg status` enabled.
Differential Revision: https://phab.mercurial-scm.org/D11907
public attribute not declared in interfaces: badpeer.badattribute
public attribute not declared in interfaces: badpeer.badmethod