#111 Add modularized matching functions

[heidmic]

• [x] rule.base
• [x] rule.initialization
• [x] matching function class
• [x] ordered bound
• [x] mutation operators
• [x] constraint handling
• [x] suprb.py
• [x] ES
• [x] RS
• [ ] (NS)

[heidmic]

I think that everything should be working now and I tried to simplify some things from the first attempts.

New matching functions need to implement:

• a function that takes data and returns the set of matched examples (as a bit string)
• a function that computes the volume matched
• a method to clip to global bounds
• a method to increase the size in each dimension to a minimal value

Additionally, for each new type of matching function a fitting way to init/update them needs to be added to rule.initialization and optimizer.rule.mutation (and optimizer.rule.ns.crossover, although I backlogged that for now as it is under rewrite anyhow). This is done with a simple addition to the pseudo switch case in the setter of the base class and the corresponding functionality in the respective inheriting classes