resolves #173 Added an inline menu macro to identify a menu selection
resolves #173 Add menu inline macro

- added menu inline macro using syntax menu:name[(item(> item)*)?]
- added menu inline macro using syntax "name( > item)+"
- added styles for menu to default stylesheet
- changed class name in HTML output for key combo to "keyseq"
- AsciiDoc compatibility configuration
- tests
Merge pull request #377 from mojavelinux/menu-inline-macro

Resolves #173 Add menu inline macro