jqGrid: IE8 bugfix
Image: thumb / original support
New column method: unsetFilterSelectOptions

To reset the <select> filter, if applied by the setReplaceValues()
Avoid double "prepare()" execution
STEP 1) Background color support: row/column + JqGrid modifications
Row color: JqGrid + Bootstrap
Tcpdf, Phpexcel, Bootstrap: Styling (row + column)
Merge branch 'master' of https://github.com/ThaDafinser/ZfcDatagrid