createTargetingModel needs '...' arguments

[Namita Gupta]

The createTargetingModel function in TargetingModels.R is essentially a wrapper for createSubstitutionMatrix and createMutabilityMatrix. However, it does not allow all arguments to each of those functions to be passed in to the wrapper function (e.g. there is no way to pass minNumSeqMutations to createMutabilityMatrix through createTargetingModel. This seems wrong and unintuitive and fixable.

[Jason Vander Heiden]

Looks like all it needed where the new arguments added in #3. The other arguments should not be adjustable. Fixed in b206436.