Use attr() instead of prop()

Check element attr for "required" rather than prop, in order to ensure IE checks this attribute. (IE doesn't consider required to be a property, only an attribute)
Allow to call public API methods with multiple parameters
Merge pull request #450 from ertrzyiks/master

Allow to call public API methods with multiple parameters
Merge pull request #447 from cs462-unikent/bug/fix-ie-required-bug

Fix for "required" field bug in IE
- added Korean Translation. bumped to 1.2.2 version
Fixed parameter name, it should be called ParsleyField instead of ParsleyForm.
Merge pull request #451 from akshar-raaj/fix_var_name

Fixed parameter name, it should be called ParsleyField instead of Parsle...
Merge branch 'master' of https://github.com/guillaumepotier/Parsley.js