Make sure we always call SetPipelineConfig when setting up a
SandboxFilter so we don't panic, and add a test to exercise this code.
Merge pull request #992 from mozilla-services/sbxmgr-filter-panic

Fixes a bug introduced by the globals change
More missed globals/pConfig-related panics.
Merge pull request #994 from mozilla-services/benchmark-panics

More missed globals/pConfig-related panics.
Separate files for encoders, filters, and decoder tests

Moves each sandbox spec into its own file.
Rename sandbox_plugins_test to all_specs_test