Implemented exposing name to runtime

Expose cycle is like this:
Scxml file: <scxml name=“somename”>
Generate scjson - return  { moduleJs, name }
Pass returned object to document-string-to-model
Pass name to Statechart constructor as opts parameter

Doesn’t crash if name parameter is not set
Added tests 323 & 324
Merge pull request #288 from jbeard4/issue-223

Issue 223, exposing _name in runtime