Changed regular expressions to allow spaces after code block delimiter

Added check for blank line underlines

Add support for globbing to INCLUDE

Fix a missed shift in INCLUDE command

This fixes an issue where a shift is not performed on a heading on the first
line of a recursively INCLUDEd file.

Supports including local code files with language tag and line
extraction.

Via #38

Fixes issue with console_scripts and distribution.
`make readme.md` and `make test` now expect markdown-pp in the $PATH,
via either `setup.py develop` or `pip install .`.