Enhance Scripting framework to allow more methods to be added to a type.

[sgtflame]

script_type<> needs to have a constructor that takes a pScriptType_type so that more methods can be added to an existing type prior to the script type being finalized.

[sgtflame]

mylyn/context/zip

[sgtflame]

Attached context. This task is essentially completed, but I'm double checking.

[sgtflame]

One caveat - script_type::attach() had to be made public, but should only be used when this new constructor is used.

Possibly eventually we should consider making a sub-class with this constructor with activate() being made public. This will make it so that if you don't use this new constructor, the activate() method is protected and can't be used incorrectly.