Sources

(nothing yet)

- You can now add a git branch at the end of a git repo line and that branch
will be checkout out, e.g.: `eol-develop git gitgithub.com:trentm/eol.git develop`.
- add "-x|--exclude-submodules" option

- [issue 5, git] Use "git submodule update --init --recursive" for recursive update
- [issue 2, git] Try running "git submodule init && git submodule update" for
git submodules after an initial clone.
- [issue 3] Better error message if running a command fails when can't find
the exe (ENOENT).

- Fix breakage from wildcard handling.

- Support glob wildcard chars in given DIRS, e.g.: `sources -l foo*`.

- Fix prog name in `sources -h` output.