Automate user/bucket creation
Add PUT Copy operation

Before this commit, cs driver uses stanchion's function to calculate S3 signature.
Because PUT Copy API uses x-amz-* headers, it become unappropriate.
So it is replaced by the function copied from erlcloud and simplified one.
Merge pull request #136 from basho/ss-cs-copy

Add PUT Copy operation to CS driver
Add increment for new-style counters.
Fix comment.

Fix an incorrect comment that happened through some copy/pasta.
Add operation to get the value of new-style counter.
Add counters configuration for 2.0+.

Add a configuration that can be modified to do benchmarking
for the new 2.0 CRDT counters.