pkg: relocate ReadTLSConfigFiles
fleetctl: ability to hide flags from usage
fleetctl: use generic names for TLS flags
fleetctl: wire up TLS for API requests
Merge pull request #1031 from bcwaldon/fleetctl-tls

fleetctl TLS for fleet API
fleetctl: new flag --ssh-timeout

This flag allows for configuration of the timeout
used during ssh connection initialization.

Fixes #1009
Merge pull request #1032 from bcwaldon/ssh-timeout

fleetctl: new flag --ssh-timeout
fleetctl: hyphens in TLS flag names
Merge pull request #1033 from bcwaldon/fleetctl-TLS

fleetctl: hyphens in TLS flag names
dep: bump golang.org/x/crypto/ssh

Move from code.google.com/p/go.crypto/ssh to
to golang.org/x/crypto/ssh before updating to
the latest commit.
Merge pull request #1036 from bcwaldon/golang.org-deps

Switch to golang.org import paths
functional: establish Member interface
functional: burn MachineConfig
functional: pass Member into Cluster methods
functional: no longer choose IDs for CreateMember
functional: drive tests with fleet API