Tighten up CSS

- Remove extra padding at top of Android bubbles, via sibling selector
- Don't include .attachments, .quote-wrapper, .content in bubble unless
  we actually need them. This allows for sibling selectors.
- This is a different technique for adding the ReactWrapperView for
  quotes - it is now appended to the DOM instead of attaching to
  something already in the DOM. This allows us to use .remove(), so it's
  a bit cleaner.
- Users of ReactWrapperView can now specify tagName and className

test/index.html

@@ -214,11 +214,16 @@
           </div>
           <div class='tail-wrapper {{ innerBubbleClasses }}'>
             <div class='inner-bubble'>
-              <div class='quote-wrapper'></div>
-              <div class='attachments'></div>
-              <div class='content' dir='auto'>
-                {{ #message }}<div class='body'>{{ message }}</div>{{ /message }}
-              </div>
+              {{ #hasAttachments }}
+                <div class='attachments'></div>
+              {{ /hasAttachments }}
+              {{ #hasBody }}
+                <div class='content' dir='auto'>
+                  {{ #message }}
+                    <div class='body'>{{ message }}</div>
+                  {{ /message }}
+                </div>
+                {{ /hasBody }}
             </div>
           </div>
           <div class='meta'>