renamed the hermite parent class files to be more readable
consistently use the word 'looping' throughout the application
refactored common code for cubic hermite splines into a base class
moved cubic hermite-related code into a subfolder for better organization
moved common quintic spline code into base classes
moved the quintic spline code to a subdirectory for better organization
added constructors to the base quintic hermite classes
gave the spline-source folder a better name
since every spline will have a looping variant the looping checkbox can go in a general area