Support API versioning. Working on #4
Support login dialog versioning. Working on #4
Fix gen_versioned_path when empty string is given
Add documentation about platform version setting
Remove useless trailing whitespaces
Update Changes
Checking in changes prior to tagging of version 1.21.

Changelog diff is:

diff --git a/Changes b/Changes
index bdde35a..8bbe418 100644
--- a/Changes
+++ b/Changes
@@ -1,6 +1,8 @@
 Revision history for Perl extension Facebook::OpenGraph

 {{$NEXT}}
+
+1.21 2014-05-03T00:15:37Z
     - Add support for API and dialog versioning that were introduced at f8

 1.20 2014-04-24T13:56:31Z