ui: pass a `ui` object to `paths.getpath`...
ui: pass a `ui` object to `paths.getpath`
I want to introduce more path's suboption and make it possible to use default
value for them. Processing theses sub-options might result in warnings. We
need a `ui` object to issue such warnings.
To make things simpler, we add an helper method on the `ui` object.
Differential Revision:
https://phab.mercurial-scm.org/D10162