Merge pull request #232 from graphitefriction/1-5-docs

updates syntax highlighting examples
minor copy fixes
Revert "Fix result of "Inline anchors" in asciidoc-syntax-quick-reference"
Merge pull request #233 from asciidoctor/revert-230-patch-1

Revert "Fix result of "Inline anchors" in asciidoc-syntax-quick-referenc...
clarify passthrough usage warning
fix tip about escaping attribute list that precedes formatted text
document how to escape unconstrained formatting marks
adds figure-caption attr to user manual

- closes asciidoctor/asciidoctor#847