resolves #594 added template to README for 0-1-4

- mentioned DocBook 5 backend in intro
- simplified OS and system requirements sections
- removed AsciiDoc vs Asciidoctor section
- added links to docs
- added IRC link
- added news link
- updated link refs in header
- split install and upgrade sections
- adjusted Rubinius version
- replaced resources section with expanded help section
- I'm a commit message monster in vim!
added missing items to 0.1.4 changelog, made other minor revisions
minor changes to CHANGELOG
Merge pull request #595 from graphitefriction/add-readme-template

resolves #594 revised README for 0.1.4, restructured to conform to new README template
README revisions
add floating heading to README for rendering on GitHub
embed changelog from latest release in README, link to full changelog
fix wording in README
modernize AsciiDoc markup example in rdoc
fix regression for multiple callouts on a single line
small optimization scanning for callouts
Merge pull request #599 from mojavelinux/multiple-callouts-on-line

fix regression for multiple callouts on a single line
fix CHANGELOG item
use untitled-label attribute as title in DocBook if document has no title
fix typo in CHANGELOG
add and honor interactive option for checklists

also:
- match options shorthand if used at beginning of style
- set cursor as default over font-based icons
render checklists in DocBook output
Merge pull request #600 from mojavelinux/interactive-checklists

add and honor interactive option for checklists
rework #455 to pass Markdown horizontal rule tests
Merge pull request #601 from mojavelinux/md-horizontal-rule-rework

rework #455 to pass Markdown horizontal rule tests