Merge pull request #13 from abdulrauf/master

Exception fixes
Merge pull request #14 from abdulrauf/master

Custom CSS for backend.
Merge pull request #15 from abdulrauf/master

S3 Mime-type improvement
Updated to version 2.6.2

Signed-off-by: Yuri Tomanek <yuri@tomanek.com.au>
migration issue fixed

comments add_column migration was breaking gb installer. I merged that migration into blog installer.