modify about page

Signed-off-by: Wei Jin <wjin.cn@gmail.com>
fix post

Signed-off-by: Wei Jin <wjin.cn@gmail.com>
fix declaration

Signed-off-by: Wei Jin <wjin.cn@gmail.com>
update Rakefile from upstream

Signed-off-by: Wei Jin <wjin.cn@gmail.com>
add post: redis introduction

Signed-off-by: Wei Jin <wjin.cn@gmail.com>