revert to hashing; refactor output proxy in preparation for using loggregator client pool

[#75468276]

Signed-off-by: Johannes Petzold <jpetzold@pivotallabs.com>
bump etcd and remove unneeded submodules

Signed-off-by: Johannes Petzold <jpetzold@pivotallabs.com>
dynamically discover loggregator servers if configured

[#75468276]

Signed-off-by: Johannes Petzold <jpetzold@pivotallabs.com>
Do not add port in health announcement

[#75468276]

Signed-off-by: Johannes Petzold <jpetzold@pivotallabs.com>
Adding *.test to gitignore

Signed-off-by: Johannes Petzold <jpetzold@pivotallabs.com>
Only start the input router if needed

[#75468276]

Signed-off-by: Johannes Petzold <jpetzold@pivotallabs.com>
move loggregator client pool into loggregatorlib

[#75468276]
Signed-off-by: Johannes Petzold <jpetzold@pivotallabs.com>
metron forwards to either traffic controller or loggregator, depending on config

[#75468276]

Signed-off-by: Johannes Petzold <jpetzold@pivotallabs.com>