added minimist handling for command line parsing + added basic support for passing filtering callback on command line
updated error handler to check error object for 'code' property before dereferencing (causing issues with some errors that did not have such a property) + updated input_content_validate to accept a function as well as an object for the callback() check + input_validate.js update to return exception on path not found + main.js to test path & check callback content before continuiing and using as filter + validation testing as above
updated testing for input_validate to take into account returning rather than throwing some errors