Replace hand-drawn icon for minimized annotations

Added menu separator between annotation and highlighting toolbar buttons

chrome/content/zotero/overlay.xul

@@ -318,6 +318,7 @@
 			<toolbarbutton id="zotero-annotate-tb-add" tooltiptext="&zotero.annotate.toolbar.add.label;" oncommand="Zotero_Browser.toggleMode(this.id);"/>
 			<toolbarbutton id="zotero-annotate-tb-collapse" tooltiptext="&zotero.annotate.toolbar.collapse.label;" oncommand="Zotero_Browser.setCollapsed(true);"/>
 			<toolbarbutton id="zotero-annotate-tb-expand" tooltiptext="&zotero.annotate.toolbar.expand.label;" oncommand="Zotero_Browser.setCollapsed(false);"/>
+			<toolbarseparator/>
 			<toolbarbutton id="zotero-annotate-tb-highlight" tooltiptext="&zotero.annotate.toolbar.highlight.label;" oncommand="Zotero_Browser.toggleMode(this.id);"/>
 			<toolbarbutton id="zotero-annotate-tb-unhighlight" tooltiptext="&zotero.annotate.toolbar.unhighlight.label;" oncommand="Zotero_Browser.toggleMode(this.id);"/>
 		</toolbar>

chrome/content/zotero/xpcom/annotate.js

@@ -680,7 +680,7 @@ Zotero.Annotation.prototype.displayWithAbsoluteCoordinates = function(absX, absY
 		this.pushpinDiv.style.cursor = "pointer";
 		// generate pushpin image
 		var img = this.document.createElement("img");
-		img.src = "chrome://zotero/skin/annotation-hidden.png";
+		img.src = "chrome://zotero/skin/annotation-hidden.gif";
 		img.title = Zotero.getString("annotations.expand.tooltip");
 		img.addEventListener("click", function() {
 			me.setCollapsed(false);