Version 1.5.0

Date: 04-Jul-2014

1. (enh #51): Enhanced GridView header and footer, to include additional headers/footers before or after default header/footer.
   The properties below can be set as an array or string:
   • Added beforeHeader property to configure additional header rows before the default grid header.
   • Added afterHeader property to configure additional header rows after the default grid header.
   • Added beforeFooter property to configure additional footer rows before the default grid footer.
   • Added afterFooter property to configure additional footer rows after the default grid footer.
2. Fixes #26 to #50.