Check return status of crypto.Init and panic on error.
Merge pull request #26 from ooyala/check-crypto-init-err

Check return status of crypto.Init and panic on error.
Rename getContainerIDsOfEnv to getContainerIDsOfShaEnv, since that's what it is.
Handle tearing down containers by env without sha properly.

Also add a TODO that this whole logic chain is broken.
go fmt.  I appear to have forgotten this step on some past commits.
Delete rules from tries correctly.

When we delete a rule from a trie, we build up the new list, with the old
rule removed.  Previously, we were building up the list by repeatedly
adding the removed rule instead of the rule we're looping over.

This leads to fun issues.
Merge pull request #28 from ooyala/fix-teardown-rule-removal

Delete rules from tries correctly.
Merge pull request #27 from ooyala/fix-teardown-env-without-sha

Handle tearing down containers by env without sha properly.
Merge branch 'master' into usage_stats_api