interfaces: drop `_ignorefiles()` from `dirstate` Protocol...
interfaces: drop `_ignorefiles()` from `dirstate` Protocol
I didn't look back at the state of things when this was introduced as a zope
interface, but the method is only called inside of `mercurial.dirstate.dirstate`
now.
In general, private methods shouldn't be in the Protocol class, but some of
these are called from outside `dirstate` by debug commands.