Added support for ".gharignore".

This file lists, one per line, fnmatch-style patterns (e.g. "README.*",
"*.txt, etc.") to ignore when creating symlinks.

This has to be a separate file and not just .gitignore because .gitignore
means that those files won't be committed and sent to upstreams. That's
OK for stuff you want to keep private, but not OK for stuff like LICENSE
and README files that you'd like to share.

For example, see https://github.com/jacobian/dotfiles
python 3 print function, urllib.parse
Support both python version urlparse library.
Explicitly check for default sub-function.

Python2's argparse, when setup to use sub-parsers, will complain when no
arguments are given. In Python3, argparse will not complain when given no
arguments and just return an empty Namespace.
Merge pull request #14 from jacobian/gharignore

Added support for ".gharignore".
fix(bin/ghar): add more helpful error for symlink fail

include the filename if we can't link.

Cleaned up version of #15 from @jacobian. Thanks.
Merge remote-tracking branch 'featheredtoast/python3-backwards-compatability-rebase'

Conflicts:
	bin/ghar
Merge remote-tracking branch 'tornewuff/fix-folder-links'

Conflicts:
	bin/ghar
Merge remote-tracking branch 'tornewuff/fix-path-discovery'
chore(ghar-bash-completion): fixup whitespace
feat(README): make it a markdown file

bring this project into 2013 with a nice looking markdown file
chore(README): fixup the thank you list
feat(README): add a contributors list
chore(README): swap around the header sizes