py3: whitelist another eight passing tests Differential Revision: https://phab.mercurial-scm.org/D2281

remotenames: port partway to python3 by using collections.MutableMapping test-logexchange.t doesn't pass after this, but at least the remotenames extension can be imported. Differential Revision: https://phab.mercurial-scm.org/D2280

tests: avoid referring to pvec in demandimport test Nothing else currently uses pvec, so we may want to delete it (but Augie Fackler says he may want to use it). To enable deletion, this patch replaces it by the error module in the demandimport test (any module works). However, since the error module had already been loaded at this point in the test (via the util module), I moved it earlier in the test so it's still not loaded (although I'm not sure if that's even relevant to the test). Differential Revision: https://phab.mercurial-scm.org/D2287

help: use cmdutil.parsealiases() to resolve command name This seems slightly better than parsing '^command|name' string by using an ad-hoc pattern.

help: list deprecated and experimental extensions if --verbose This is common in the other help topics.

hgweb: translate Abort in help command to 404 error c3784e3c3e8d changed the exception type to be raised if unknowncmd=False.

templatekw: add {reporoot} keyword The "%b" in filename format string will be replaced with "{reporoot|basename}".

templatefilters: add dirname() filter This is different from stripdir() in that the last component is always removed.

templater: add function to help substituting patterns in template string This will be used to rewrite a filename pattern to a template string.

templater: extract function scanning template string This provides a tokenizer-level view of template fragments, and will be used to substitute patterns in outermost 'string' tokens.