Transmit node metadata to component instances, fixes #145
Add spec for default value
Add type information test cases
Add spec for required ports
Take into account error port
Add spec for out ports
Spec out buffered port
Add spec for enumerated value port
Add spec for shorthand
Processing function called with port as context
Processing shorthand should also accept options
Add spec for component shorthand
Merge pull request #150 from kenhkan/port-api

Port API specs
Syntax fix
Validate port datatypes
Fix processing function tests
Implement port default values, fixes #149
Support for pull ports
Validate enumerated values
Fix component API tests