branching: merge stable into default

tests: normalize the way some debug output it matched Differential Revision: https://phab.mercurial-scm.org/D11361

tests: drop hgrc bits that have become the default Differential Revision: https://phab.mercurial-scm.org/D11247

tests: manual cleanup now that dummyssh usage is implied Differential Revision: https://phab.mercurial-scm.org/D11246

tests: rely on dummyssh being the default This commit is exactly the result of running this command: sed -i -e 's! *\(-e \|--ssh \|--config ui.ssh=\)[ \"]*$PYTHON[ \"]*$\(RUN\|\)TESTDIR/dummyssh[\"]* *! !g' -e '/^[ >]*ssh *=[ "]*$PYTHON[ "]*$\(RUN\|\)TESTDIR\/dummyssh[ "]*$/d' -e 's/^\( [$] .*[^ ]\) *$/\1/' *.t *.sh Sometimes the tests can be simplified further, but I think it's preferable to do the simplification separately. Differential Revision: https://phab.mercurial-scm.org/D11245

tests: setup dummyssh as the default ssh To significantly reduce boilerplate in tests. One test is updated to show that it works, I expect to do the rest in follow up commits. Differential Revision: https://phab.mercurial-scm.org/D11244

dirstate: drop the `_otherparent` method It only has one caller with a lot of the logic already implemented. So lets inline it and cleans things up further. Differential Revision: https://phab.mercurial-scm.org/D11353

dirstate: drop the `_normal` method It only has one caller so lets inline it and cleans things up further. Differential Revision: https://phab.mercurial-scm.org/D11352

dirstate: drop the `_merge` method It only has one caller that only use one of the branch, so lets inline that branch and clean things up further. Differential Revision: https://phab.mercurial-scm.org/D11351

dirstate: drop the deprecated `drop` method eh ;-) Differential Revision: https://phab.mercurial-scm.org/D11350