Version 0.14

+ Fixed 'Multiple' elements overwriting each other.
+ Renamed the "XSDValidatorUtility.xsd" to
"XSDValidatorSimpleTypes.xsd".
+ Implemented 'Keyword' element. Changed the "XSDValidator.xsd",
"XSDValidatorComplexTypes.xsd",   "XSDValidatorSimpleTypes" and all XML
(.brk) files to work with the new structure.
+ Implemented 'Reference' element. Applies to every element from the XSD
that is under key-keyref restriction. Uses the name of the element to
create the list (e.g. all 'material' elements).
+ Added controls to all 'Group Elements' for better handling in the
Element Viewer.
+ Fixed the order of the Element Viewer. (Multiple elements no longer
appear in the bottom)