test-https: test web.cacerts functionality

serve: fix https mode and add test The https mode failed in super because BaseRequestHandler is an old-style class. This introduces the first test of https client/server functionality - and "hghave ssl". The test is currently only run on Python 2.6.

hgweb: don't send a body or illegal headers during 304 response Without this fix, mod_wsgi and spawning get in a wedged state after sending a 304 response. Not sending a body fixed that problem. The header change was discovered by using wsgiref.validate.validator to check for other errors.

merge with stable

test-url: skip test when ssl module is unavailable

revset: use 'requires' instead of 'wants' in error message

outgoing: unify common graphlog.outgoing and hg.outgoing code

bundlerepo: unify common code into a new getremotechanges The pattern where we fetch incoming remote changes and return them as a local bundlerepo seems common. It's nicer to have this code unified.

revset id(): fix error text to say "id wants..." instead of "rev wants..."

keyword: only use expensive fctx.cmp when needed Restrict expensive cmp to cases when: - comparing against working directory and - encode filters active or - path is configured for keyword expansion