New Structure, fixes for mx5.7 and Template Grid

New Feature:
support for template grid; empty message and dynamic show of paging

Bug Fixes for mx5.7
Detection Reference Set selector, broken by new 5.7 class for testing.
Broken compare check for stored Flex Columns in Mx5.7 (no settings for
column attr anymore )
Broken sorting in Mx5.7 (th domData, changed from key to, index and use
of _visibleColumns) replaced buildGridBody only compatible with mx5.7
and up