first (untested) cut at a copy server
use active manifest in manual test
use index instead of length for End in riak_cs_get_fsm:continue/1
use base64 encoded MD5 for riak_cs_put_fsm:finalize/2
PUT copy of objects and maultipart upload, including acl and policy checking

with:

- multipart upload-copy with ACL control
- special copy condition and range in multipart_upload
- release note mentions as technical preview
- add more permission tests
- anonymous access cannot copy secret file to public space
discussion fix on #868;

- add size limitation
- stop the get_fsm_pid in upload part
- MD5 checksum won't be checked if any range specified
- add boto test code
- fix corner case with source multipart upload on put copy with range
Merge pull request #868 from basho/feature/copy-object-server-rebased

copy object server rebased

Reviewed-by: shino