Revisions: Bunch of refactoring and code cleanup

* Extracted a lot of model-y stuff from the view code.
* Slider now has a proper model, with communication with other models.
* Use of `get( foo )` instead of `findWhere({ id: foo })`.
* Properly set the `from` diff when routing single mode.
* Bind `prev()` and `next()` to their model.
* Tick marks are now percentage based, which means the slider resizes with the browser, without JS resize events.
* When scrubbing, the position of the scrubber is considered a hover, so you can fall off the timeline while still scrubbing and the tooltips will persist.
* Tooltips fade in and out.
* Tooltips hang around for a grace period instead of immediately going away. More forgiving.
* Unused code paths removed.
* Got rid of a bunch of view-to-view communication.
* Use `_.times()` instead of a `for` loop.
* Removed premature `Math.floor()` and `Math.ceil()` calls that were making things not add up to 100%.

See #24425.

git-svn-id: https://develop.svn.wordpress.org/trunk@24658 602fd350-edb4-49c9-b593-d223f7449a82

wp-admin/css/colors-fresh.css

@@ -1391,7 +1391,7 @@ table.diff .diff-addedline ins {
 }
 
 .revisions-tickmarks > div {
-	background-color: #ccc;
+	border-color: #aaa;
 }
 
 #diff-title-to strong {

wp-admin/css/wp-admin.css

@@ -2549,15 +2549,19 @@ tr.wp-locked .row-actions .trash {
 tr .locked-info {
 	height: 0;
 	opacity: 0;
-	-webkit-transition: height 1s, opacity 500ms;
-	transition:         height 1s, opacity 500ms;
 }
 
 tr.wp-locked .locked-info {
 	height: 22px;
 	opacity: 1;
-	-webkit-transition: height 1s, opacity 500ms 500ms;
-	transition:         height 1s, opacity 500ms 500ms;
+}
+
+tr.locked-info, tr.wp-locked .locked-info {
+	-webkit-transition: height 1s, opacity 500ms;
+	-moz-transition:    height 1s, opacity 500ms;
+	-ms-transition:     height 1s, opacity 500ms;
+	-o-transition:      height 1s, opacity 500ms;
+	transition:         height 1s, opacity 500ms;
 }
 
 .fixed .column-comments .sorting-indicator {
@@ -3512,14 +3516,22 @@ td.plugin-title p {
 	height: 0.8em;
 	z-index: 2;
 	top: 7px;
+	width: 70%;
+	box-sizing: border-box;
 }
 
 .revisions-tickmarks > div {
-	height: 0.8em;
-	width: 1px;
-	float: left;
 	position: relative;
+	height: 100%;
+	float: left;
 	z-index: 10002;
+	border-style: solid;
+	border-width: 0 0 0 1px;
+	box-sizing: border-box;
+}
+
+.revisions-tickmarks > div:first-of-type {
+	border-left-width: 0;
 }
 
 .comparing-two-revisions .revisions-controls {
@@ -3654,6 +3666,14 @@ table.diff .diff-addedline ins {
 	padding: 4px;
 }
 
+.revisions-tooltip.fade {
+	-webkit-transition: opacity 200ms;
+	-ms-transition:     opacity 200ms;
+	-moz-transition:    opacity 200ms;
+	-o-transition:      opacity 200ms;
+	transition:         opacity 200ms;
+}
+
 .comparing-two-revisions .revisions-tooltip {
 	bottom: 145px;
 }