Support function templates

ui-grid fails when template is defined as a function, for example:
$templateCache.put('ui-grid/uiGridCell', function (elem, attrs) {
            return "<div class=\"ui-grid-cell-contents\" title=\"TOOLTIP\">{{COL_FIELD CUSTOM_FILTERS}}</div>"
        });

Author: mirik123

src/js/core/services/gridClassFactory.js

@@ -112,6 +112,7 @@
              templateGetPromises.push(gridUtil.getTemplate(col[providedType])
                 .then(
                 function (template) {
+                  if ( angular.isFunction(template) ) { template = template(); }
                   var tooltipCall = ( tooltipType === 'cellTooltip' ) ? 'col.cellTooltip(row,col)' : 'col.headerTooltip(col)';
                   if ( tooltipType && col[tooltipType] === false ){
                     template = template.replace(uiGridConstants.TOOLTIP, '');
@@ -224,4 +225,4 @@
       return service;
     }]);
 
-})();
+})();