This attempts to retrieve cloudconfigs from two sources: the meta-data
service, and the user-data service. If only one cloudconfig is found,
that is applied to the system. If both services return a cloudconfig,
the two are merged into a single cloudconfig which is then applied to
the system.
Only a subset of parameters are merged (because the meta-data service
currently only partially populates a cloudconfig). In the event of any
conflicts, parameters in the user-data cloudconfig take precedence over
those in the meta-data cloudconfig.
Supports retries with exponential backoff as well as connection
timeouts and the ability to skip SSL/TLS verification.
This commit also refactors datasource and initialize packages
in order to use the new HTTP client.
