run-tests: move replacements generation into Test The API is a bit funky. Things will look better once all state is captured in Test.

run-tests: move testtmp into Test class This patch starts the process of moving test-specific variables into the Test class. The ultimate goal is to be able to instantiate a Test with minimal arguments and to call run() on it without too much thinking. This will make it much easier to run tests from other contexts. It will also enable things like running a test multiple times.

run-tests: create classes for representing tests Currently, the state for an individual test is scattered across a number of functions and variables. This patch begins a process of isolating a single test's state into instances of a class. It does this by establishing a new Test base class and child classes for Python tests and T tests. The class currently has a run() API that proxies into the existing "runner" functions. Upcoming patches will move the logic for each test type into the class.

revsetbenchmark: add `author(mpm) or author(lmoscovicz)` to the canonical list This matters as `author(mpm)` have a lot of matches evenly split in the repo, while `author(lmoscoviz)` have less match (and later). This changes the execution path of the "or" operator a lot.

filterpyflakes: filter WindowsError unconditionally

filterpyflakes: make memoryview filtering unconditional

py3kcompat: drop unused export

py3kcompat: don't convert os.environ to bytes os.environ accepts str not bytes. Assigning bytes will result in a run-time error.

demandimport: pass proper level to __import__ in Python 3 demandimport was failing in Python 3 with a ValueError because __import__'s level=-1 has gone away (-1 means to try both relative and absolute imports and relative imports don't exist in Python 3). With this patch, demandimport still doesn't work in Python 3 (it fails when importing a non-package module).

help: suggest keyword search when no topic is found When `hg help foobar` fails, it now suggests using `hg help --keyword foobar` instead of printing a full page of basic commands. This should greatly increases discoverability of the `hg help --keyword` argument.