[Frontend] Manual re-do of collapse/expand panes

open #90
Major work on new .mini-tab elements, used
as controls to expand/collapse panes;
Cleaned up splitter hover behavior;
Changed mixin controlGrippy to not be tied
to :before;

platform/commonUI/general/res/sass/user-environ/_layout.scss

@@ -252,6 +252,36 @@
             top: $ueTopBarH + $interiorMarginLg + $treeSearchInputBarH + $interiorMargin;
         }
     }
+    .mini-tab.toggle-pane {
+        $h: $ueTopBarH;
+        $paneOffset: $interiorMarginLg * -3;
+        //font-size: 0.7rem;
+        //position: absolute;
+        //height: $h;
+        //line-height: $h;
+        top: 5px;
+        z-index: 2;
+        &.toggle-tree.anchor-left {
+            //@include test(green);
+            left: $paneOffset;
+/*            &:hover {
+                left: $paneOffset - 2;
+            }*/
+            &:after {
+                content:'F';
+            }
+        }
+        &.toggle-inspect.anchor-right {
+            $xpos:  $paneOffset + $interiorMargin;
+            right: $xpos;
+/*            &:hover {
+                right: $xpos - 2;
+            }*/
+            &:after {
+                content:'F'; //\e612
+            }
+        }
+    }
     &.items {
         .object-browse-bar {
             .left.abs,
@@ -289,7 +319,6 @@
                 }
             }
         }
-
     }
 }
 
@@ -358,46 +387,20 @@
 // right representation.
 .browse-hidetree {
     @include user-select(none);
-    // Sets the left tree menu when the tree
-    // is hidden.
+    // Sets the left tree menu when the tree is hidden.
     .pane.left.treeview {
         opacity: 0;
-        //right: 100% !important;
-        //width: auto !important;
-        //overflow-y: hidden;
-        //overflow-x: hidden;
     }
-    // Sets the right represenation when
-    // the tree is hidden.
+    // Sets the right represenation when the tree is hidden.
     .pane.right-repr {
         left: 0 !important;
     }
 }
 
 .browse-showtree {
-    // NOTE: DISABLED SELECTION
-    // Selection disabled in both panes
-    // causing cut/copy/paste menu to
-    // not appear. Should me moved in
-    // future to properly work
-    //@include user-select(none);
-
     // Sets the left tree menu when the tree is shown.
     .pane.left.treeview {
         @include trans-prop-nice(opacity, .4s);
-        //@include background-image(linear-gradient(90deg, rgba(black, 0) 98%, rgba(black, 0.3) 100%));
         opacity: 1;
-        //display: block !important;
-        //width: auto !important; // CH CO
-        //right: auto;
-        //width: $proporMenuWithView;
-    }
-    // Sets the right representation when the tree is shown.
-    .pane.right-repr {
-        //left: $proporMenuWithView;
-        //width: auto !important;
-
-        //left: 0 !important;
-        //transform: translateX($proporMenuWithView);
     }
 }