Fix CSS linear-gradient syntax

the first argument to linear-gradient is required to either be an angle, or expressed as "to [side]". Omitting the "to" keyword causes gradients to not render in IE10.

select2.css

@@ -53,7 +53,7 @@ Version: @@ver@@ Timestamp: @@timestamp@@
     background-image: -webkit-linear-gradient(center bottom, #eee 0%, #fff 50%);
     background-image: -moz-linear-gradient(center bottom, #eee 0%, #fff 50%);
     filter: progid:DXImageTransform.Microsoft.gradient(startColorstr = '#ffffff', endColorstr = '#eeeeee', GradientType = 0);
-    background-image: linear-gradient(top, #fff 0%, #eee 50%);
+    background-image: linear-gradient(to top, #fff 0%, #eee 50%);
 }
 
 .select2-container.select2-drop-above .select2-choice {
@@ -65,7 +65,7 @@ Version: @@ver@@ Timestamp: @@timestamp@@
     background-image: -webkit-linear-gradient(center bottom, #eee 0%, #fff 90%);
     background-image: -moz-linear-gradient(center bottom, #eee 0%, #fff 90%);
     filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#ffffff', endColorstr='#eeeeee', GradientType=0);
-    background-image: linear-gradient(top, #eee 0%, #fff 90%);
+    background-image: linear-gradient(to top, #eee 0%, #fff 90%);
 }
 
 .select2-container.select2-allowclear .select2-choice .select2-chosen {
@@ -191,7 +191,7 @@ Version: @@ver@@ Timestamp: @@timestamp@@
     background-image: -webkit-linear-gradient(center bottom, #ccc 0%, #eee 60%);
     background-image: -moz-linear-gradient(center bottom, #ccc 0%, #eee 60%);
     filter: progid:DXImageTransform.Microsoft.gradient(startColorstr = '#eeeeee', endColorstr = '#cccccc', GradientType = 0);
-    background-image: linear-gradient(top, #ccc 0%, #eee 60%);
+    background-image: linear-gradient(to top, #ccc 0%, #eee 60%);
 }
 
 .select2-container .select2-choice .select2-arrow b {
@@ -236,7 +236,7 @@ Version: @@ver@@ Timestamp: @@timestamp@@
     background: url('select2.png') no-repeat 100% -22px, -webkit-gradient(linear, left bottom, left top, color-stop(0.85, #fff), color-stop(0.99, #eee));
     background: url('select2.png') no-repeat 100% -22px, -webkit-linear-gradient(center bottom, #fff 85%, #eee 99%);
     background: url('select2.png') no-repeat 100% -22px, -moz-linear-gradient(center bottom, #fff 85%, #eee 99%);
-    background: url('select2.png') no-repeat 100% -22px, linear-gradient(top, #fff 85%, #eee 99%);
+    background: url('select2.png') no-repeat 100% -22px, linear-gradient(to top, #fff 85%, #eee 99%);
 }
 
 .select2-drop.select2-drop-above .select2-search input {
@@ -248,7 +248,7 @@ Version: @@ver@@ Timestamp: @@timestamp@@
     background: url('select2-spinner.gif') no-repeat 100%, -webkit-gradient(linear, left bottom, left top, color-stop(0.85, #fff), color-stop(0.99, #eee));
     background: url('select2-spinner.gif') no-repeat 100%, -webkit-linear-gradient(center bottom, #fff 85%, #eee 99%);
     background: url('select2-spinner.gif') no-repeat 100%, -moz-linear-gradient(center bottom, #fff 85%, #eee 99%);
-    background: url('select2-spinner.gif') no-repeat 100%, linear-gradient(top, #fff 85%, #eee 99%);
+    background: url('select2-spinner.gif') no-repeat 100%, linear-gradient(to top, #fff 85%, #eee 99%);
 }
 
 .select2-container-active .select2-choice,
@@ -273,7 +273,7 @@ Version: @@ver@@ Timestamp: @@timestamp@@
     background-image: -webkit-linear-gradient(center bottom, #fff 0%, #eee 50%);
     background-image: -moz-linear-gradient(center bottom, #fff 0%, #eee 50%);
     filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#eeeeee', endColorstr='#ffffff', GradientType=0);
-    background-image: linear-gradient(top, #fff 0%, #eee 50%);
+    background-image: linear-gradient(to top, #fff 0%, #eee 50%);
 }
 
 .select2-dropdown-open.select2-drop-above .select2-choice,
@@ -285,7 +285,7 @@ Version: @@ver@@ Timestamp: @@timestamp@@
     background-image: -webkit-linear-gradient(center top, #fff 0%, #eee 50%);
     background-image: -moz-linear-gradient(center top, #fff 0%, #eee 50%);
     filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#eeeeee', endColorstr='#ffffff', GradientType=0);
-    background-image: linear-gradient(bottom, #fff 0%, #eee 50%);
+    background-image: linear-gradient(to bottom, #fff 0%, #eee 50%);
 }
 
 .select2-dropdown-open .select2-choice .select2-arrow {
@@ -437,7 +437,7 @@ disabled look for disabled choices in the results dropdown
     background-image: -webkit-gradient(linear, 0% 0%, 0% 100%, color-stop(1%, #eee), color-stop(15%, #fff));
     background-image: -webkit-linear-gradient(top, #eee 1%, #fff 15%);
     background-image: -moz-linear-gradient(top, #eee 1%, #fff 15%);
-    background-image: linear-gradient(top, #eee 1%, #fff 15%);
+    background-image: linear-gradient(to top, #eee 1%, #fff 15%);
 }
 
 .select2-locked {
@@ -519,7 +519,7 @@ html[dir="rtl"] .select2-container-multi .select2-choices li
     background-image: -webkit-gradient(linear, 0% 0%, 0% 100%, color-stop(20%, #f4f4f4), color-stop(50%, #f0f0f0), color-stop(52%, #e8e8e8), color-stop(100%, #eee));
     background-image: -webkit-linear-gradient(top, #f4f4f4 20%, #f0f0f0 50%, #e8e8e8 52%, #eee 100%);
     background-image: -moz-linear-gradient(top, #f4f4f4 20%, #f0f0f0 50%, #e8e8e8 52%, #eee 100%);
-    background-image: linear-gradient(top, #f4f4f4 20%, #f0f0f0 50%, #e8e8e8 52%, #eee 100%);
+    background-image: linear-gradient(to top, #f4f4f4 20%, #f0f0f0 50%, #e8e8e8 52%, #eee 100%);
 }
 html[dir="rtl"] .select2-container-multi .select2-choices .select2-search-choice
 {