Change behavior of DirectiveLineProcessor to display an error if directives such as #load or #r are used after code
Change ThrowIfAfterCode to BehaviourAfterCode on DirectiveLineProcessor to give implementers choice of how to handle directives used after code
Switch to custom exception InvalidDirectiveUseException for Throw behaviour in DirectiveLineProcessor
Merge branch 'dev' of https://github.com/scriptcs/scriptcs into invalid-load-notice
Merge pull request #478 from dpen2000/invalid-load-notice

Fixes #470