Fixes type of argument index

Issue: #32
Fixes TSmalltalkInstruction::serialize()

Issue: #32
Fixes indentation in InstructionDecoder

Issue: #32
Adds stub instruction skipping logic

Issue: #32
Fixes BasicBlock::getTerminator()

Issue: #32
Fixes ParsedBytecode::parse()

Issue: #32
Moves some code of TSmalltalkInstruction class from headers into .cpp file

Removes TInstruction from types.h.
Adds method TSmalltalkInstruction::toString().

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