resolve issue #16 - use prefix block_ for block element templates
set attribute for default encoding
rework templates to be more complete and handle whitespace better

- fill out the templates to be more complete by including ids, titles, roles, etc
- fix tests to align with the standard templates
- be more sane about what whitespace and indentation is being included in output
embed asciidoc stylesheet if stylesheet attribute is set and empty
support book doctype, streamline doc title accessors

- add doctype accessor to Document
- support the book doctype (multiple level-0 headings)
- polish and document logic for retrieving the document and header titles
- subtitute attributes in section titles
- tests for everything mentioned above
make ruler a block, make comments handling more robust

- treat ruler as a block
- make sure trailing endlines after comment don't create an empty paragraph
- drop empty blocks when parsing blocks
- grab content of line comment for future use
- move comments tests to blocks test
merge upstream changes
parse header metadata (author, revision info)

- parse author information from first line following document title
- parse revision information from second line following document title
- add reader method to consume comments so they can be stepped around
- add reader method to check for the document title section
- update tests to header metadata semantics
- tests for all of the above ;)
remove unnecessary reader instantiation
unshift collection of lines to preserve order
mindfully use empty? instead of any? for efficiency
Revert embed asciidoc stylesheet
Merge upstream changes
Merge pull request #22 from mojavelinux/ruler-and-comments

Ruler and comments
add Gemfile to enable `bundle install` for setup

- the Gemfile simply redirects bundler to the information in the gemspec
- to bootstrap, you just run: git clone {repo}, bundle install, rake
No /bin/env on this here Mac
Remove json dependency
Update gemspec
Add rake to gemspec for Travis' benefit
Remove .travis.yml and see if Travis has everything he needs from the Gemfile now