Feature : Add gen_uptoken().
Feature : Make call_with_multipart_from() capable of acceptig files.
Feature : Add QBox::RS::upload().
Feature : Make it possible to replace the host in an authorized put url with a customed one.
Improve : Add new policy fields, and filter out defined fields.
BugFix : Merge $auth->{policy} independently.
Debug : [] -> ().
Improvement : Add url params.
BugFix : Use correct function.
Feature : Use specific up_host returned from the up server in subsequent bput calls.
Refactory : Passing arguments.
Refactory : Disable rs.drop service.
Merge pull request #3 from BluntBlade/master

定期提交。