Spinner: Trivial spelling / grammatical fixes in CSS comments.

Author: tjvantoll

themes/base/jquery.ui.spinner.css

@@ -38,13 +38,13 @@
 	overflow: hidden;
 	right: 0;
 }
-/* more specificity required here to overide default borders */
+/* more specificity required here to override default borders */
 .ui-spinner a.ui-spinner-button {
 	border-top: none;
 	border-bottom: none;
 	border-right: none;
 }
-/* vertical centre icon */
+/* vertically center icon */
 .ui-spinner .ui-icon {
 	position: absolute;
 	margin-top: -8px;