Move the entities data into its own file.
Clean up Rakefile and associated stuff (packaging and docs).
Clean up whitespace in lib/maruku.rb.
Merge branch 'master' into cleanup

Conflicts:
	Rakefile
	maruku_gem.rb
Get rid of the marudown executable. It's obsoleted by the maruku executable.
Clean up bin/maruku.
Check for a few error conditions in bin/maruku.
Make bin/marutex call out to bin/maruku.
Make the executables work without manual load-path munging.
Get rid of the old attic directory.
Add an option to bin/maruku for outputting markdown.
Get rid of a remaining html file.
Re-indent maruku/attributes.rb.
Clean up maruku/attributes.rb.
Re-indent maruku/defaults.rb.
Clean up maruku/defaults.rb.
Re-indent maruku/errors_management.rb.
Clean up maruku/errors_management.rb.
Rename maruku/errors_management.rb to maruku/errors.rb.
Reindent maruku/helpers.rb.