Simplify the CreateExperimentDialog

[pfleck]

The internal logic of the CreateExperimentDialog is fairly complex to support all the different Parameter types, showing the variation options and creating all the variations over all parameters. To simplify the internal logic of the CreateExperimentDialog the different functionalities should be split and made available outside the GUI.

Some thoughts:

• Variator-classes for each parameter type to encapsulate the possible values for that patameter. Views for the variator-classes to show the possible parameter values.
• The CreateExperimentDialog gets a list of parameter values for each parameter. Then the cross product of those parameter value lists is generated.

[swagner]

In this regard we should also check, if some parts of the meta-optimization branch can be refactored/reused/integrated for that purpose (e.g. ParameterConfigurationTree, etc.). At least we should take the chance and create a common infrastructure for describing, manipulating, generating algorithm and problem parameters, that can be used for the CreateExperimentDialog and for meta-optimization.