* Move the watch package into the api module
It was already just a thin wrapper around the API anyways. The biggest change was to the testing. Instead of using a test agent directly from the agent package it now uses the binary on the PATH just like the other API tests.
The other big changes were to fix up the connect based watch tests so that we didn’t need to pull in the connect package (and therefore all of Consul)
- Includes some bug fixes for previous `api` work and `agent` that weren't tested
- Needed somewhat pervasive changes to support hash based blocking - some TODOs left in our watch toolchain that will explicitly fail on hash-based watches.
- Integration into `connect` is partially done here but still WIP
This patch fixes watch registration through the config file and a broken log line when the watch registration fails. It also plumbs all the watch loading through a common function and tweaks the
unit test to create the watch before the reload.
When a -dev agent is restarted it'll have a clean state, including a
reset index. A watch() will reconnect after a restart, but it won't
notice that the index counter has reset and it will keep waiting until
we reached the old index again, which is wrong. Resetting the index will
prevent that and makes watch work for -dev agents.