Log Message:
Update ruby-maruku to version 0.5.8.  Chanages from version 0.5.6 include:

+ Install as a Ruby gem.

* Fixed bugs:
  * Fix bug in which links `<http://..>` at beginning of lines could
    sometimes be mistaken for HTML.
  * Empty cells in table are now allowed.
  * Now this is accepted (Maruku did not like the "." inside the link)
	[a. b] is a link.

	[a. b]: http://site.com/
* Fix bug about double-encoding of ampersands in code blocks.
* Fixed compatibility bug with Ruby 1.8.6 patchlevel 110.