pony-indent now behaves like other indent-line-functions.

In Emacs, the point moves to the end of indentation if the point came
before the first non-whitespace character in a line. Otherwise, the
point stays put, relative to the text.
Use which-func instead of python-current-defn.

python-current-defun isn't present in all python modes that may be in
use, but this should be resolved by using which-func.  See issue #65.
Allow projects to specify additions to the pythonpath.

.dir-locals pony-settings can now inlcude a pythonpath option that
is passed to manage.py using --pythonpath. --pythonpath will only
be passed if it is included in the project.
Bind default-directory instead of using cd

Using `cd' in this way causes the `default-directory' for the buffer
where whichever command that calls `cd' was started to be changed
permanently, using `cd' to switch it back didn't work because there
would be called in a different buffer.

For use with `shell-command*' just let-binding `default-directory'
should be enough to ensure shell commands run in the right directory.
Update AUTHORS for pull #68
Merge branch 'custom-pytonpath' of https://github.com/SoftwareMaven/pony-mode
Update authors for Travis Jensen
Update docs to reflect new pythonpath dir-locals code
Merging indent-line tweak for tpl mode.
refs #57
Add Simon Law to AUTHORS
Merge branch 'master' of https://github.com/markhepburn/pony-mode into which-fun
Add Simon Hepburn to AUTHORS