analytic: changed analytic solution for discs (still not perfect)
magcreator: added logo function
phasemap: revised the analytical formulas -> more uniform
added new folder for PYRAMID project
added testsuite module

Holoimaging and phasemap now have separate display functions
Display_combine implemented in main.py
Changed sqrt(x^2 + y^2) to np.hypot(x,y)
magcreator now uses <= instead of <
pdb starts on error (implemented in main.py)

Now calls cells by their index instead of the real coordinates (first step
toward "one-time-call" of the F-function and lookup afterwards)

Changed the way parameters are given to magcreator functions (now as tuples)
Implemented the real space approach to get phase images (works, but slow!)