Updated imagen and featuremapper submodule references
Brought OpenMP documentation up to date
Updated param submodule reference
Updated som_retinotopy data for training tests

Python hash function (used when time_dependent=True) was found to be
platform specific. A new platform-independent hash has been implemented,
modifying the random streams and requiring new reference training data.
Updated param submodule reference
Reintroduced updated som_retinotopy.ty_DATA file for training tests
Updated dataviews, imagen and featuremapper submodule references
Updated all submodule references in external
Updated version check in setup.py
Updated param, imagen and featuremapper submodule references
Updated call to verify method of __version__ in setup.py
Moved testpatterngenerator unit tests to imagen/tests
Moved testsheetview unit tests to dataviews/tests
Moved testnumbergen unit tests to param/tests
Moved testboundingregion unit tests to dataviews/tests
Moved testparameterizedobject unit tests to param/tests
Converted testNumberParameter doctests to unit tests in param/tests
Converted testDynamicParameter doctests to unit tests in param/tests
Converted testParamOverrides doctests to unit tests in param/tests
Converted testCompositeParameter doctests to unit tests in param/tests