This patch adds a new extension point to pydev which will allow plugins to contribute custom PYTHONPATH entries to a python project. Whenever the project python path is requested, contributions will be asked to provide any additional path entries.
Use Case: I want to ship a Python library/sdk as an Eclipse/Pydev plugin. If my Eclipse Python library plugin is installed, I want the SDK to automatically available to pydev projects, just as though it were installed as a python system lib.
This change allows the plugin to contribute the SDK, which makes the SDK code known to the AST manager *and* adds the SDK directory to the runtime PYTHONPATH.