demo(tooltip): correct usage of anchor element

Tooltips were nested in anchor elements to get the hyperlink styling
from Bootstrap. This seems like an odd use of anchor elements and we
shouldn't encourage this. Instead, use anchors like actual links that
point to nowhere (#).

Closes angular-ui#1507
Closes angular-ui#1509

Author: chrisirhc

src/tooltip/docs/demo.html

@@ -8,22 +8,22 @@
       <input type="text" ng-model="dynamicTooltip" class="form-control">
     </div>
     <p>
-      Pellentesque <a><span tooltip="{{dynamicTooltip}}">{{dynamicTooltipText}}</span></a>,
+      Pellentesque <a href="#" tooltip="{{dynamicTooltip}}">{{dynamicTooltipText}}</a>,
       sit amet venenatis urna cursus eget nunc scelerisque viverra mauris, in
       aliquam. Tincidunt lobortis feugiat vivamus at 
-      <a><span tooltip-placement="left" tooltip="On the Left!">left</span></a> eget
+      <a href="#" tooltip-placement="left" tooltip="On the Left!">left</a> eget
       arcu dictum varius duis at consectetur lorem. Vitae elementum curabitur
-      <a><span tooltip-placement="right" tooltip="On the Right!">right</span></a> 
+      <a href="#" tooltip-placement="right" tooltip="On the Right!">right</a> 
       nunc sed velit dignissim sodales ut eu sem integer vitae. Turpis egestas 
-      <a><span tooltip-placement="bottom" tooltip="On the Bottom!">bottom</span></a> 
+      <a href="#" tooltip-placement="bottom" tooltip="On the Bottom!">bottom</a> 
       pharetra convallis posuere morbi leo urna, 
-      <a><span tooltip-animation="false" tooltip="I don't fade. :-(">fading</span></a>
+      <a href="#" tooltip-animation="false" tooltip="I don't fade. :-(">fading</a>
       at elementum eu, facilisis sed odio morbi quis commodo odio. In cursus
-      <a><span tooltip-popup-delay='1000' tooltip='appears with delay'>delayed</span></a> turpis massa tincidunt dui ut.
+      <a href="#" tooltip-popup-delay='1000' tooltip='appears with delay'>delayed</a> turpis massa tincidunt dui ut.
     </p>
 
     <p>
-      I can even contain HTML. <a><span tooltip-html-unsafe="{{htmlTooltip}}">Check me out!</span></a>
+      I can even contain HTML. <a href="#" tooltip-html-unsafe="{{htmlTooltip}}">Check me out!</a>
     </p>
 
     <form role="form">