fix bug in redirect
update Gemfile.lock
Update README.rdoc

add introduction for creating bucket
Update README.rdoc

add introduction for getting an object's temporary url
add methods for bucket policy
Update README.rdoc

add introduction for methods work with bucket policy
update url
update url method
Update README.rdoc

add introduction to get the url for a public accessible object
Update README.rdoc
[update object.save && object.copy]:add clever support in conent_type setting;add support for x-snda-meta-*
add dependency mime-types
Update README.rdoc

add smart support for content_type 
add support for x-snda-meta-*
Merge with git://github.com/grandcloud/sndacs-ruby.git