bookmarks: hide dict behind bmstore class This should make it clearer that the bmstore doesn't expose all dict APIs.

tests: remove pid file by default Previously, killdaemons.py would kill PIDs listed in a file then leave the file lingering around. If the PIDs are killed, then there's no point leaving the PID file around. In the worst case, a later invocation of killdaemons.py (run-tests.py invokes killdaemons.py after running a test) could kill a separate process whose PID conflicted with a previously-killed process. By removing the PID file, we eliminate this possibility. Some tests were manually removing the PID file after calling killdaemons.py. So we update these tests to not do this. Differential Revision: https://phab.mercurial-scm.org/D3443

tests: remove #require killdaemons The killdaemons hghave feature has returned True since it was introduced in 448d0c452140. As such, "#require killdaemons" has no effect and is superfluous. So we remove instances of it. Differential Revision: https://phab.mercurial-scm.org/D3442