added validate method directly on schema class
added start for schemadot
removed unused createSchema function
initialize enumValues and schemaDependencies at schema construction
added _pathsEncountered to ensure no recursive loops in references
fixed validation references to typeList, enumValues to check lengths not just null
schemadot - lots of cleanup/making sausage
added new tests
added README.md
added some examples
updated createSchemaFromUrl to load from local filesystem if (non-http and (file or no scheme))