Handle standard menu items defined by Nodes in the browser.

The File menu now includes a "Create" submenu, and Delete/Rename
options. Nodes can offer Delete/Rename functionality, and the
options on the menu are automatically enabled/disabled based on
the selected node. Each node can also offer Create functionality,
and specify a list of node types (including itself) from which the
option should be made available. The menu is dynamically generated
based on the selected node.

The Context menu on the treeview works in a similar way, except that
nodes can offer any context menu items (we don't allow this on the
top menu, as that should stay consistent to avoid user confusion).

web/pgadmin/static/css/overrides.css

@@ -67,4 +67,62 @@ iframe {
 /* Prevent tree items wrapping */
 .aciTree .aciTreeItem {
     white-space: nowrap !important;
+}
+
+/* Disabled menu items */
+.mnu-disabled {
+    color: #999999 !important;
+}
+
+/*
+ * Bootstrap 3 remove submenus as they don't work overly well on Mobile. The 
+ * following CSS adds them back in - for our purposes they actually work fine
+ * on Mobile and are perfectly responsive
+ */
+.dropdown-submenu {
+    position:relative;
+}
+
+.dropdown-submenu>.dropdown-menu {
+    top:0;
+    left:100%;
+    margin-top:-6px;
+    margin-left:-1px;
+    -webkit-border-radius:0 6px 6px 6px;
+    -moz-border-radius:0 6px 6px 6px;
+    border-radius:0 6px 6px 6px;
+}
+
+.dropdown-submenu:hover>.dropdown-menu {
+    display:block;
+}
+
+.dropdown-submenu>a:after {
+    display:block;
+    content:" ";
+    float:right;
+    width:0;
+    height:0;
+    border-color:transparent;
+    border-style:solid;
+    border-width:5px 0 5px 5px;
+    border-left-color:#cccccc;
+    margin-top:5px;
+    margin-right:-10px;
+}
+
+.dropdown-submenu:hover>a:after {
+    border-left-color:#ffffff;
+}
+
+.dropdown-submenu.pull-left {
+    float:none;
+}
+
+.dropdown-submenu.pull-left>.dropdown-menu {
+    left:-100%;
+    margin-left:10px;
+    -webkit-border-radius:6px 0 6px 6px;
+    -moz-border-radius:6px 0 6px 6px;
+    border-radius:6px 0 6px 6px;
 }

web/pgadmin/static/css/wcDocker/theme.css

@@ -144,6 +144,7 @@
 
 .wcMenuList, .context-menu-list {
   border: 1px solid #dddddd;
+  z-index: 999 !important;
 }
 
 .wcMenuItem, .context-menu-item {
@@ -201,3 +202,7 @@
 .wcLayout, .wcLayout tr, .wcLayout td {
     vertical-align: top;
 }
+
+.context-menu-submenu:after {
+  content: '>' !important;
+}