Update the message header to include optional hmac information
Merge branch 'dev' into features/message_signing
Merge in the dev branch and add tests for message signing

The config should look like this
[TCP:5565]
type = "TcpInput"
address = "127.0.0.1.5565"
    [signer.trink_0]
    hmac_key = "4865ey9urgkidls xtb0[7lf9rzcivthkm"
Clean up duplication in unit test code
Add signer verification to the message matcher
Update flood to support message signing

- Moved the flood configuration into a toml file (the command line
options were becoming too numerous).  Various sections can be created
and referenced by name so it can store all the test configurations
Add sandbox_manager_filter for dynamic control of sandbox filters

- start/stop functionality only (messages will be missed during
the cycle).  Replace (no message loss) will have to be pushed out
to the next release

- sbmgr allows a user specified sandbox to be loaded/unloaded
- sbmgrload allows a number of instances of a hard coded sandbox to
be loaded/unloaded
Merge branch 'dev' into features/message_signing

Conflicts:
	pipeline/config.go
	pipeline/inputs_test.go
	pipeline/mock_outputrunner_test.go
	pipeline/mock_pluginhelper_test.go
	pipeline/pipeline_runner.go
Don't leak pipeline configs btn tests, remove unnecessary selects.
re-add the explicit "ok" check.
Remove `getTestPipelinePack` since it isn't useful in the general case w/o leaking
PipelineConfig setup btn test environments.
Fix TCPInput exit issues

- Read error no longer infinitely loops
- Run will not exit until all handleConnection routines are finished
Merge branch 'features/message_signing' of github.com:mozilla-services/heka into features/message_signing
Move test utilities into their own subdirectory

- use a named return for err
Add waitgroup to track WhisperRunners in the WhisperOutput so we can be
deterministic about knowing when things have shut down (fixes test failures that
started after go's new scheduler landed).
Merge branch 'dev' of github.com:mozilla-services/heka into dev
Add MGI internal channel data to the heka report.
Incorporate review feedback

- update docs
Merge branch 'dev' into features/message_signing

Conflicts:
	testsupport/mock_net_conn.go
Add pre-requisites for building heka.