conftest.py: set HGPLAIN=1 and GIT_PAGER=cat, remove now-obsolete --no-pager
testing: tidy up setting and asserting author fields
test_push_email: new xfail, email address is dropped on push
Strictly match author/committer field and capture email address (fixes test_push_email)

This regex attempts to precisely matches the specification given in
git-fast-import(1). With the old regex, the line

    "author Some Git <name@example.org> 1358978816 -0600"

produces

    user = "Some Git "

which ends up being pushed to Hg without the email. If the patch comes
back to git, it'll become "Some Git <unknown>", which causes
problems.
Add failing test_push_two_commits
Add failing test_simple_push_updates_remote
sh.git: bake in _tty_out=False to prevent color regardless of user config

An alternative is to set it per repository via

    git config color.ui never

but it's conveniont for this setting to be global.
Merge pull request #17 from jedbrown/strict-author-with-email

Strictly match author/committer field and capture email address
Merge pull request #19 from jedbrown/new-failing-tests

New failing tests