* Groundwork for basic VM tracing.
* RPC endpoint for VM tracing and ser/de types ready.
* Create VMTracer trait.
* Rearchitected VM tracing to reflect existing tracing.
Should more or less work now.
* Integrated VM tracing into JSONRPC.
* Fix ethcore module tests.
* Add tests for VM tracing.
* Fix consensus test code.
* Fix mock tests.
* Added VM trace information for post-execution stuff.
* Fix max-value calls and add "creates" field to getTransaction.
* Tests for VM tracing.
* Don't implement the trait with unimplemented.
* Remove invlaid comment.
* Fix tests.
* Basic hex block exporting.
* Export formats and to file.
* First bits.
* Block importing.
* Fix error text.
* Wait for queue to empty before shutting down after import.
