Restores PushBlock instruction processing

Issue: #32
Adds comparison operator for TSmalltalkInstruction and isValueX accessors

Issue: #32
Adds consumer analysis part of control graph optimizer

Issue: #32
Builds all graph* and parsed* code into a separate libstapi

Issue: #32
Add stub for tests

Issue: #32
Adds test for TSmalltalkInstruction

Issue: #32
Adds tests for InstructionDecoder

Issue: #32
Adds tests for ControlGraph

Issue: #32