resolves #1090 assign title to preface node

- assign title to preface node based on value of preface-title attribute
resolves #749 handle subs option thoroughly in block constructor
Allow docinfo to be in separate directory from content

Resolves #511
cleanup Section constructor
enable CI reports

- code coverage (locally & for shippable.com builds) (use `rake coverage test:all`)
- JUnit-style XML reports (for shippable.com builds)
upgrade thread_safe gem to 0.3.4
Merge pull request #1190 from mojavelinux/shippable-ci-reports

enable CI reports
assign Hash default using property assignment to make Nashorn happy
Merge pull request #1155 from mojavelinux/issue-1090

resolves #1090 assign title to preface node
Merge pull request #1184 from mojavelinux/issue-749

resolves #749 handle subs option thoroughly in block constructor
resolves #1103 allow numeric characters in block attribute name

- allow numeric characters in block attribute name (per name token spec)
- use character constants to define regex in AttributeList class
update GC settings in benchmark
resolves #1198 add explicit to_s call to generate math delimiter config
resolves #1106 honor empty cell at end of table row
Merge pull request #1199 from mojavelinux/issue-1198

resolves #1198 add explicit to_s call to generate math delimiter config
Merge pull request #1197 from mojavelinux/issue-1103

resolves #1103 allow numeric characters in block attribute name
Merge pull request #1200 from mojavelinux/issue-1106

resolves #1106 honor empty cell at end of table row
Updated font-awesome CDN refs bump 4.2.0 adding 40 new icons
Merge pull request #1201
Merge pull request #1189 from Mogztter/issue-511

Allow docinfo to be in separate directory from content