[ENH] Added functions to display god rays visual effects and calculate outcomes

You can obtain
. God rays visual effects
. Outcomes including Numbers of Skin Polygons, Numbers of Approachable Polygons and Approachable Score.

You can use not only a target point but also a target model to calculate outcomes.
[ENH] Added a function to erase MRMLDisplayNode
Removed RemovePathModel function
[ENH] Added a slider bar
[ENH] Added a variable range for the slider bar
[ENH] Test codes to see tuples
[ENH] Added function to obtain point coordinates for displaying each needle path individually
[Modified] single path display was modified.
[BugFix]
[Updates] Updated UI
Update:
Delete: Cleaned all files
ENH: Added new source codes.
Merge branch 'ayamada0614-master'

Conflicts:
	PercutaneousApproachAnalysis/PercutaneousApproachAnalysis.py
	PercutaneousApproachAnalysis/PercutaneousApproachAnalysis.pyc