Rss feed subscription

As Oalders's suggestion on #327 we have had RSS feed and we should make it more visible as well as tweak the author feed. So what I have done in this pull request are
  
  - The author feed will be like 'author's activity' feed, the activity includes 
  <ol>
  <li>This author has released a module</li> 
  <li>This author ++ed a module.</li>
  </ol>
  Example feed from my RSS reader
   
![screenshot 2014-06-17 01 47 28](https://cloud.githubusercontent.com/assets/1759054/3291767/d983dfa6-f587-11e3-9fca-a8afb17f92aa.png)

 - Make RSS feed button be more visible
 <ul> 
   <li>On **/author** and **/recent** page I put the RSS button to the top of the table as well as add page header.
![author_rss_header_with_subscription](https://cloud.githubusercontent.com/assets/1759054/3292083/758a0738-f58b-11e3-9775-5c6e8b000662.png)
</li>
<li>On **module** page I put subscription button on the dependencies section as 
![subscript_to_distribution](https://cloud.githubusercontent.com/assets/1759054/3292100/9275f28a-f58b-11e3-8581-927a5c3faf9b.png)
</li>
</ul>

any comment about the function and design ? Could you check. :)