footnotes, special sections and lists

- implement the footnote and footnoteref macros
- add footnote template
- store the footnotes in the document references
- add a reified footnotes section to the footer
- add support for special sections, flag them as such
- add a numbered caption to appendix sections
- don't number special sections if numbered is on
- add templates for special lists (glossary, qanda and bibliography)
- support bibliography anchors
- fix extra blank lines being added in labeled lists
- tests for all that
fix author name with single quote
use blockquote tag for quote blocks
restrict document from enabling icons in SECURE mode
use callout icons if icons enabled
remove the class attribute on the blockquote tag
tests for lists with multiple adjacent line comments
ignore blank lines at beginning of document
Add rbx to builds
Merge pull request #136 from mojavelinux/patch-1

Add rbx to builds
Merge pull request #135 from mojavelinux/header-fix

Ignore blank lines at beginning of document
Merge pull request #131 from mojavelinux/lock-icons

Restrict document from enabling icons in SECURE mode
Merge pull request #129 from mojavelinux/footnotes-and-special-blocks

Footnotes, special sections and special lists
Merge pull request #133 from mojavelinux/list-with-comments-tests

tests for lists with multiple adjacent line comments
Merge pull request #132 from mojavelinux/blockquote

Use blockquote tag for quote blocks
Merge pull request #130 from mojavelinux/callout-icons

Use callout icons if icons enabled