resolves #59 asciidoctor manual of attributes and values

- add user manual links to index pagenitial draft of asciidoctor production guide
- created table of attributes in processors and compat file
- created initial draft of asciidoctor user manual
- incorporated 0-1-4 features
- related to issue #43
switch source highlighter to CodeRay, fix spacing in exampleblock
corrected source lang errors
Merge pull request #100 from graphitefriction/production-ref

resolves #59 asciidoctor manual of attributes and values
fix callouts example in syntax quick ref
release notes draft
first set of revisions
second set of revisions
reorganize sections
add intro and outro
trim icons section; move cuts to separate file; restore select cuts
add section about extensions
copyedited release notes

- removed lots of _justs_
- changed AsciiDoc to Asciidoctor in checklist section
- added backend repo link
- expanded 87 to word
- added C-style and Lisp examples to callouts
- changed callout highlighting section title
- spellchecked
- changed group to float-group
edits and reordering of release notes
minor edit to xref example
fix info about prewrap, add toc, add source lang where missing
update stats
rename 0.1.4 announcement file
update styles, add support for multiple authors to new entry partial
final revisions