Merge pull request #995 from nasa/timeline-913a

R&I tweaks to Timeline scrollbar and splitters

platform/features/timeline/res/sass/_timelines.scss

@@ -23,6 +23,13 @@
 .l-timeline-holder {
     @include absPosDefault();
 
+    &.split-layout {
+        >.splitter {
+            // Top of splitter within Timelines should be 0
+            top: 0;
+        }
+    }
+
     .l-header {
         @include user-select(none);
         cursor: default;
@@ -58,7 +65,7 @@
                 }
                 &.l-tabular-r {
                     // Start, end, duration, activity modes columns
-                    @include scrollH();
+                    @include scrollH(scroll);
                     left: $timelineTabularTitleW;
 	                .l-width {
 		                @include absPosDefault(0, visible);
@@ -304,11 +311,6 @@
 		}
 	}
 
-    .splitter {
-        // Top of splitter within Timelines should be 0
-        top: 0;
-    }
-
 	// Ticks
 	.l-ticks,
 	.l-subticks {
@@ -331,4 +333,4 @@
     &:hover {
         background-color: $colorItemTreeHoverBg;
     }
-}
+}