added installation variable, initialize it when zookeeper is setup
Merge pull request #130 from datacratic/installation_service_base

added installation variable, initialize it when zookeeper is setup
PLAT-670: ensure that StreamingUploadSource/StreamingDownloadSource own their shared_ptr<S3Api>
Removed declaration of S3Api::streamingDownload/Upload
HttpClient: the interface now exposes the number of requests that are currently queued
tcp_client: renamed "address" to the more meaninful "hostname"
Merge branch 'master' into http-client-ih

Conflicts:
	service/http_client.cc
	service/http_client.h