end-to-end from upr interface to indexer endpoint.

Patchset-3:
- changed NewHTTPServer() to use timeout values from const.go
- improved logging.

Patchset-4:
- UPR client requirements.
- golint fixes.

Patchset-5:
- adminport changes, test cases.

Patchset-6:
- minor bugfixes
- test cases for streamlib loopback, dropdata, timeout
- benchmark streamlib loopback.
- goformating for indexing/adminport/*.go

Patchset-7:
- UpdateMutationStreamRequest implements Subscriber interface.
- refactored GetEvaluators() and GetRouters() methods.

Patchset-8:
- Implemented review comments.

Patchset-9:
- refactored projector to scale with vbuckets, instead of engines.
- use bucket-code mapping to identify {bucket, vbuckets} over a connection.
- better log messages.

Patchset-10:
- removed BucketCode based bucket identification.
- implemented John's second set of comments.

Change-Id: I2f5453eca18522c37a64e944dcdf063ce4173ea6
Reviewed-on: http://review.couchbase.org/37037
Reviewed-by: John Liang <johliang00@gmail.com>
Reviewed-by: Pratap Chakravarthy <prataprc@couchbase.com>
Tested-by: Pratap Chakravarthy <prataprc@couchbase.com>