Commit 2.7 release notes.

Update getting started guide for 2.7

llvm-svn: 102412

llvm/docs/GettingStarted.html

@@ -726,6 +726,7 @@ revision), you can checkout it from the '<tt>tags</tt>' directory (instead of
 subdirectories of the '<tt>tags</tt>' directory:</p>
 
 <ul>
+<li>Release 2.7: <b>RELEASE_27</b></li>
 <li>Release 2.6: <b>RELEASE_26</b></li>
 <li>Release 2.5: <b>RELEASE_25</b></li>
 <li>Release 2.4: <b>RELEASE_24</b></li>