Correct versions in development
Merge branch 'master' into development

* master:
  Update README.md
Simplified exception handling
Simplified exception handling
Updating version to 1.3.1 in prep for v2beta3 release
Adding info on running SBML test suite
More comments
Adding license: LGPL
Merge pull request #5 from NeuroML/development

Merge to master for NeuroML v2beta3 release