Shellquote arguments to `honcho run`

Again emulating Foreman behaviour, this patch quotes incoming arguments to
honcho run, which makes it possible to pass in arguments with spaces:

    honcho run git commit -m "hello world"

N.B. This does break compatibility with honcho 0.2.0, as it means that
arguments will no longer be interpolated in the shell. In honcho 0.2.0:

    $ NAME=world honcho run echo 'Hello $NAME'
    Hello world

Now:

    $ NAME=world honcho run echo 'Hello $NAME'
    Hello $NAME
Merge pull request #25 from mgax/run-args

Shellquote arguments to `honcho run`
Replace README.md with README.rst
Bump version -> v0.3.0
Fix setup.py
Bump version -> v0.3.1
Windows support for honcho

A number of honcho features assumed a POSIX platform. This commit adds support
for running honcho on Windows-based platforms, and adds a `honcho.compat` module
as a place to centralise any platform-specific helper functions.

Closes #30.
Bump version -> v0.4.0
First pass at improving Honcho's documentation
Update the README to point to the docs on RTFD
Fix README link typo
Add supervisord export

This commit adds support for exporting from Procfile to [supervisord][] format.

[supervisord]: http://supervisord.org/

Closes #31.
Make more format strings 2.6-compatible
Merge pull request #36 from hannesstruss/master

Made some more format strings 2.6 compatible