EASearch now has a simple cache of previously evaluated options, these are not evaluated again
Improved EASearch

Improved mutation operator (now Gaussian mutation on float and int
options, random mutation on set options).
The maximum number of option evaluations can be set.
Debugged the creation of instances from the archive

Also, added a class for surrogate mutation operator. Does nothing so far
(trains the model, but otherwise only copies parents to offspring).