Ordering: Add case-insensitive options natural sort plugin.

Merge pull request #301 from freak3dot/master
Resolves #281

sorting/natural.js

@@ -94,6 +94,10 @@ function naturalSort (a, b, html) {
 }
 
 jQuery.extend( jQuery.fn.dataTableExt.oSort, {
+	"natural-ci-pre": function ( a ) {
+		return a.toString().toLowerCase();
+	},
+
 	"natural-asc": function ( a, b ) {
 		return naturalSort(a,b,true);
 	},
@@ -108,6 +112,14 @@ jQuery.extend( jQuery.fn.dataTableExt.oSort, {
 
 	"natural-nohtml-desc": function( a, b ) {
 		return naturalSort(a,b,false) * -1;
+	},
+
+	"natural-ci-asc": function( a, b ) {
+		return naturalSort(a,b,true);
+	},
+
+	"natural-ci-desc": function( a, b ) {
+		return naturalSort(a,b,true) * -1;
 	}
 } );