Adds distinct and borrow to the one and only true index.
Documents shortcut array syntax. Refs #397.
Adds docutils modules to lib index, fixes :idx: markers.
Wraps variables inside `when` for macosx. Refs #461.
implemented large parts of the 'not nil' checking
resolved conflict; added missing files
Merge pull request #475 from gradha/pr_macosx_gnu_readline

Wraps variables inside `when` for macosx. Fixes #461.
Merge pull request #473 from gradha/pr_doc_improvements

Doc improvements
fixes 465
made tests green