Don't wrap in an AND qualifier if there is only one qualifier.
Change constructor parameters from private to private final.
javadoc
Adds minor change and 2 properties to enable indented pretty-print JSON response and to set indentation space count.

Handy for development and easily legible curl json responses in console.
Properties:
	er.rest.format.ERXJSONRestWriter.shouldPrettyPrint=false (set to true to enable)
	er.rest.format.ERXJSONRestWriter.prettyPrintIndent=2 (or your preferred indent)
Make constant values final
Fix test for Memory, which throws "not implemented"  exceptions on certain SQLExpression calls.