By correctly handling content type negotiation, we can avoid the
need for a special version of watch and use the same code path as
typed clients.
Kubernetes-commit: 3f94f80b0a79293e54d7080aaf7a64d7df8b1d4a
There was no reason to have two types and this avoids ~10% of allocations
on the GET code path.
```
BenchmarkGet-12 100000 109045 ns/op 17608 B/op 146 allocs/op
BenchmarkGet-12 100000 108850 ns/op 15942 B/op 132 allocs/op
```
Kubernetes-commit: 0489d0b1cf139253b82f73b072578073bc5616d6
