WIP Vertical indentation lines for RAML

- Only supports indent size of 2
- Lines do not extend into markdown, XML, or JSON
- TODO Lines do not extend through wrapped lines
  (most common in markdown)
- Lines will extend into other content when using
  a root mediaType because of a pre-existing bug
  setting mode given a root mediaType (see Bug
  62872896)
HACK Correct indentation for schema/example

TODO We really shouldn't set mode until we
encounter schema or example (rather than the
parent). Then we wouldn't need the optional indent
param hack or the if(/(schema|example)… hack
Fix: Lines work through wrapped lines

Also added missing semi-colon