revset: add an optimised baseset.__contains__ (issue4371)

The baseset class is based on a python list. This means that base.__contains__
was absolutely as crappy as list.__contains__. We now rely on __contains__ from
the underlying set.

This will avoid having to explicitly convert the baseset to a set (using
baseset.set()) whenever one want fast membership test.

Apparently there is already code that forgot to do such conversions since we
observe a massive speedup in some test.

revset #25: roots((0::) - (0::tip))
0) wall 2.079454 comb 2.080000 user 2.080000 sys 0.000000 (best of 5)
1) wall 0.132970 comb 0.130000 user 0.130000 sys 0.000000 (best of 65)

No regression is observed in benchmarks.

This change improve the issue4371 back to acceptable situation (but are still
slower than manual substraction)

--HG--
branch : stable
keepalive: fix how md5 is used

The code in keepalive dates from when it was importing the md5 module directly
and uses md5.new. Since then, what 'md5' means has been changed from an import
of the md5 module to being a function using the right module between hashlib
and md5, so the md5.new idiom doesn't work anymore.

--HG--
branch : stable
extra : rebase_source : 6dd12da0965733433490d89fd1239040e54721af
hgweb: fail if an invalid command was supplied in url path (issue4071)

Traditionally, the way to specify a command for hgweb was to use url query
arguments (e.g. "?cmd=batch"). If the command is unknown to hgweb, it gives an
error (e.g. "400 no such method: badcmd").

But there's also another way to specify a command: as a url path fragment (e.g.
"/graph"). Before, hgweb was made forgiving (looks like it was made in
44c5157474e7) and user could put any unknown command in the url. If hgweb
couldn't understand it, it would just silently fall back to the default
command, which depends on the actual style (e.g. for paper it's shortlog, for
monoblue it's summary). This was inconsistent and was breaking some tools that
rely on http status codes (as noted in the issue4071). So this patch changes
that behavior to the more consistent one, i.e. hgweb will now return "400 no
such method: badcmd".

So if some tool was relying on having an invalid command return http status
code 200 and also have some information, then it will stop working. That is, if
somebody typed foobar when they really meant shortlog (and the user was lucky
enough to choose a style where the default command is shortlog too), that fact
will now be revealed.

Code-wise, the changed if block is only relevant when there's no "?cmd" query
parameter (i.e. only when command is specified as a url path fragment), and
looks like the removed else branch was there only for falling back to default
command. With that removed, the rest of the code works as expected: it looks at
the command, and if it's not known, raises a proper ErrorResponse exception
with an appropriate message.

Evidently, there were no tests that required the old behavior. But, frankly, I
don't know any way to tell if anyone actually exploited such forgiving behavior
in some in-house tool.

--HG--
branch : stable
extra : rebase_source : 3400fe8c6a8beb84a359c4ce4f585814a700d745