clfilter: ensure that mq performs commits on unfiltered repos

clfilter: use unfiltered repo for bookmark push logic The remote location of the bookmark may be filtered locally. This changeset ensures that bookmark movement logic has access to all the repo's content.

clfilter: `bookmark.validdest` should run on unfiltered repo The logic recently added to `bookmark.validdest` uses data about obsolete changesets to see if a bookmark destination is valid. Obsolete changesets are likely to be filtered, so we need to work on an unfiltered repository.

clfilter: unfilter some parts of the push logic Computation of common changesets during push needs to be done on the widest set possible. An unfiltered version of the repo is kept for discovery and various revset calls. The discovery code itself enforces the filtering of unserved outgoing changeset.

subrepo: add argument to "diff()" to pass "ui" of caller side (issue3712) (API) Color extension achieves colorization by overriding the class of "ui" object just before command execution. Before this patch, "diff()" of abstractsubrepo and classes derived from it has no "ui" argument, so "diff()" of hgsubrepo uses "self._repo.ui" to invoke "cmdutil.diffordiffstat()". For separation of configuration between repositories, revision 573bec4ab7ba changed the initialization source of "self._repo.ui" from "ui"(overridden) to "baseui"(plain) of parent repository. And this caused break of colorization. This patch adds "ui" argument to "diff()" of abstractsubrepo and classes derived from it to pass "ui" object of caller side.

clfilter: prevent unwanted warning about filtered parents as unknown During changectx __init__ the dirstate's parents MAY be checked. If the repo is filtered, this check will complain "working directory has unknown parents" even if the parents are perfectly known. This may happen when the repo is used for serving and the dirstate has parents that are secret, as those secret changesets will be filtered.

clfilter: strip logic should be unfiltered Strip is a "write" operation that needs to be aware of the whole repo's content before destroying changesets. Only the low level function is altered. The top level command will still process its argument filtered (if any filtering is in place).

clfilter: verify logic should be unfiltered To verify a changelog obviously needs all of it. The verify logic now ensures it works on an unfiltered repository.