chore() Remove more pieces of Opera < 15 support and document it

Author: realityking

docs/content/misc/faq.ngdoc

@@ -50,7 +50,7 @@ Yes. See instructions in {@link downloading}.
 
 ### What browsers does Angular work with?
 
-We run our extensive test suite against the following browsers: Safari, Chrome, Firefox, Opera,
+We run our extensive test suite against the following browsers: Safari, Chrome, Firefox, Opera 15,
 IE9 and mobile browsers (Android, Chrome Mobile, iOS Safari). See {@link guide/ie Internet
 Explorer Compatibility} for more details in supporting legacy IE browsers.
 

src/ng/sniffer.js

@@ -24,7 +24,7 @@ function $SnifferProvider() {
         document = $document[0] || {},
         documentMode = document.documentMode,
         vendorPrefix,
-        vendorRegex = /^(Moz|webkit|O|ms)(?=[A-Z])/,
+        vendorRegex = /^(Moz|webkit|ms)(?=[A-Z])/,
         bodyStyle = document.body && document.body.style,
         transitions = false,
         animations = false,

test/ng/snifferSpec.js

@@ -254,8 +254,7 @@ describe('$sniffer', function() {
           body : {
             style : {
               WebkitTransition : transitionStyle,
-              MozTransition : transitionStyle,
-              OTransition : transitionStyle
+              MozTransition : transitionStyle
             }
           }
         };