B-48943 - Update api-validator configuration to match translation when configuration xsl-engine

Updating the Config objec to accept the following
- select XSD engine as "Xerces" or "SaxonEE"
- select XSL engine as "Xalan", "XalanC", "SaxonHE" or "SaxonEE"

Deprecated the following
- Config.setUseSaxonEEValidation
- Config.getUseSaxonEEValidation
- Config.useSaxonEEValidation
B-48943 -  Update api-validator configuration to match translation when configuration xsl-engine

- Updating Config to accept "Saxon" for xslEngine to maintain compatibility
- Adding tests to verify Config object maintains backward compatibility
B-48943 - Update api-validator configuration to match translation when configuration xsl-engine

- Updating Config object as per Jorge's requests.
Merge pull request #162 from usnavi/xsd-engine

   B-48943 - Update api-validator configuration to match translation when configuration xsl-engine
Prep for release.
Merge pull request #163 from InABlender/prep

Prep for release.
[maven-release-plugin] prepare release api-checker-1.0.9
[maven-release-plugin] prepare for next development iteration
Updated todo.
Added support for JSON schema in the XSDs.
Added JSON grammar check to config.
Add support for json-schema check in XSL.
Updated CLI tools for JSON checks.
Ensure only a single default JSON schema is assigned.
Updated TODO.
Created JSON schema check state.
Initial support for JSON Schema check in step-builder.
Better handling of error messages in JSON schema.
Use JSONNode instead of token buffer.
Updated json-schema-validator for better messages.