phabricator: rename a variable to clarify that it is the parent filecontext Differential Revision: https://phab.mercurial-scm.org/D8219

phabricator: pass old `fctx` to `addoldbinary()` instead of inferring it Currently, removed binaries aren't marked as binaries on the left side, which sends the raw file view to a bad URL in the web interface. (See D8009) In order to handle marking the file as binary in the removed case, both contexts need to be provided by the caller, since there is no current fctx in the removed case. Having an explicit old fctx will also be useful to support a `--no-stack` option that rolls up the commit stack into a single review. The bug isn't fixed with this change- there's a missing call to it in `addremoved()` as well. But instead of spamming the list with a bunch of test diffs, all of the missing binary issues will be fixed at once later. Differential Revision: https://phab.mercurial-scm.org/D8218

phabricator: make `hg phabread` work outside of a repository This is similar to 16312ea45a8b and 2513f0f70a26- we don't need a repo, but will load .hg/hgrc if inside one. Differential Revision: https://phab.mercurial-scm.org/D8214

phabricator: refactor `phabread` to write all patches at once This will be necessary to create a first class `phabimport` command. That command requires a transaction, and will import all named patches within a single transaction. But if Phabricator queries also happen within the transaction, that leaves open the chance that an exception is raised, the transaction is abandoned, and the next command that is run will complain about needing to run `hg recover`. Differential Revision: https://phab.mercurial-scm.org/D8135

phabricator: make `hg phabupdate` work outside of a repository This is similar to 16312ea45a8b- we don't need a repo, but will load .hg/hgrc if inside one. Differential Revision: https://phab.mercurial-scm.org/D8208

phabricator: pass ui instead of repo to `userphids()` Also not a repository operation. Differential Revision: https://phab.mercurial-scm.org/D8207