Add MATLABDatasetConverter

Created a ConvertService plugin for automatically converting Datasets to
MatlabNumericArrays, which can then be translated to a MATLAB matrix.
Create MATLABNumericArrayPreprocessor

Added a preprocessor for automatically populating MatlabNumericArray
@Parameters.
Create ImageJMATLABCommands

Added a MATLABCommands plugin for providing convenience methods within
MATLAB.
Create integration tests

Added two integration test classes (IT because they require a valid
MATLAB install and thus should not be run as part of the build).

One can be run within or without MATLAB, the other must be run from
within MATLAB.