Import fixed and some documentation added in python POLDI scripts

	modified:   Code/Mantid/Framework/PythonInterface/plugins/algorithms/PoldiProjectAddDir.py
	modified:   Code/Mantid/Framework/PythonInterface/plugins/algorithms/PoldiProjectAddFile.py
	modified:   Code/Mantid/Framework/PythonInterface/plugins/algorithms/PoldiProjectRun.py

Refs #100