Enhancements for cascading comboboxes (issue 504)

For issue 504 (https://github.com/hikalkan/jtable/issues/504), I modified my working version to allow dependsOn for any input field type (not just comboboxes) and to prefill cascading dropdown w/previous value if match in new options. I also fixed a typo in an error message and updated the dev source with these changes (plus the change from pull request #332). However I did not yet regen the minified (jquery.jtable.min.js) file with the code changes (just the typo).