fixed instantiation of abstract class
fixed removing users on user management page
Button styling according tao v3 standarts
Backward compatibility for fileuploader improved,
fixed issue with drag'n'drop to upload control in Chrome, client mime validation in IE
fixed issues with saving form state after failed validation, fixed name conflicts in form elements, validation added for required field
Visual improvements
Phpdoc updated
Validators can be applied during import process, added login validation for csv importing of testtakers
Merge pull request #56 from oat-sa/TP-292

Added validation during testtakes importing process.part of http://forge.taotesting.com/issues/3164