Merge pull request #374 from mozilla-services/features/no-stat-prefix

No longer require that stats be prefixed w/ the 'stats' namespace.
basic multidecoder should work now
added default Catchall logic to the MultiDecoder in the event that a message was not properly decoded by any contained decoder.
send log messages to the standard logger if a DecoderRunner is not available
bind the name of the decoder into the MultiDecoder
check that MultiDecoder loads into it's own DecoderWrapper
added a test to verify that a MultiDecoder with a single subdecoder works as expected
append ".catchall" to the Message.Type prior to re-injecting the pack into the pipeline
added test for catchall for the MultiDecoder
added testcase to verify that if Catchall is disabled, MultiDecoder will log an error and recycle the PipelinePack.
re-enabled all pipeline testcases
Merge branch 'dev' into features/multidecoder

Conflicts:
	pipeline/decoders_test.go
added docs for MultiDecoder
Generate a reasonable default working directory for SandboxManagerFilter if none is
explicitly specified.
Typo.
Figure sandbox filter file paths relative to the Heka base_dir.
Don't use a separate default working dir for each sbx manager since they'll
namespace the files themselves.
Merge pull request #392 from mozilla-services/features/sandbox-base-dir

Features/sandbox base dir
Merge branch 'dev' into features/multidecoder
Updated toml dependency, removed `CatchAll` option, added `log_sub_errors`
option, removed panic recovery.
Bump toml dependency SHA again.
Merge pull request #389 from mozilla-services/features/multidecoder

Features/multidecoder