fix(tooltip): incorrect position when text wraps

The $digest that was removed in 32c470 is actually necessary to get the
tooltip contents rendered. The rendered content is important when the
tooltip is on the right edge. See Plunker in angular-ui#2995:
http://plnkr.co/edit/8GZ5F5zj3Xe6IinXQz74?p=preview

Reverts change in 32c470 (angular-ui#2995) but fixes it in another way.

Fixes angular-ui#2995
Fixes angular-ui#2992
Fixes angular-ui#2951
Closes angular-ui#2996

Author: chrisirhc

src/tooltip/tooltip.js

@@ -189,14 +189,7 @@ angular.module( 'ui.bootstrap.tooltip', [ 'ui.bootstrap.position', 'ui.bootstrap
 
               // Set the initial positioning.
               tooltip.css({ top: 0, left: 0, display: 'block' });
-
-              // Now we add it to the DOM because need some info about it. But it's not
-              // visible yet anyway.
-              if ( appendToBody ) {
-                  $document.find( 'body' ).append( tooltip );
-              } else {
-                element.after( tooltip );
-              }
+              ttScope.$digest();
 
               positionTooltip();
 
@@ -236,7 +229,13 @@ angular.module( 'ui.bootstrap.tooltip', [ 'ui.bootstrap.position', 'ui.bootstrap
                 removeTooltip();
               }
               tooltipLinkedScope = ttScope.$new();
-              tooltip = tooltipLinker(tooltipLinkedScope, angular.noop);
+              tooltip = tooltipLinker(tooltipLinkedScope, function (tooltip) {
+                if ( appendToBody ) {
+                  $document.find( 'body' ).append( tooltip );
+                } else {
+                  element.after( tooltip );
+                }
+              });
             }
 
             function removeTooltip() {