Update post-receive for changed Environment class.

Environment.get_envelopesender() Was renamed to get_sender() in
1a1cafdcf8, then in 4de195dd40 converted into a sender attribute.
Update post-receive to work with the current version.

Two original patches squashed by: Michael Haggerty <mhagger@alum.mit.edu>
Change git log args to be backwards compatible

Also, -M is implied by -C so -M is removed
Merge pull request #4 from chrishiestand/master

Fix git log arguments to be backwards compatible with older versions of git
Move .gitignore to the top-level directory.

The git project's top-level .gitignore already ignores "*.py[co]", so
a .gitignore file will not be needed if it is integrated into that
project.
Improve the summary of the project in README.
Add a minimal setup.py.

Also add some entries for packaging outputs to .gitignore.
Add MANIFEST.in file.
Add classifiers and keywords.
Use the README file as the long description.
Merge branch 'python-packaging'

Add some infrastructure to allow the project to be registered with
PyPI and installed using distutils et al.
call 'git log -p', not 'git log --patch' (unavailable in old Git)

'--patch' was introduced as a synonym for '-p' in Git v1.7.2.
Merge pull request #5 from moy/log-dash-p

call 'git log -p', not 'git log --patch' (unavailable in old Git)
add space after [repo_shortname] in emailprefix
README: use CamelCase for option names

Git option names are case-insensitive. CamelCasing (Capital on first
letter of each word) makes them more readable without changing the
meaning. This is the convention in "man git-config" already.
README: say explicitly that "reference change" emails are called "refchange"
README: Mention announce emails in the introduction
mention git_multimail (not post-receive) in message when not in a repository
Merge pull request #7 from moy/missing-space

add space after [repo_shortname] in emailprefix
Fix indentation of paragraphs within enumerated list.
Merge branch 'doc'

The list of config options starts being a bit long.

This branch tries to make it more readable and easier to go through,
by making the link between the 1. / 2. (and now 3.) enumeration at the
top and the list of options.

Perhaps it's time to introduce sections/subsections in the list too,
but I didn't do that.