Fix comment indentation
Add a few FuncSpec tests for simple examples
Add tests for 'ODEsystem.set' method
Convert 'mapsystem_test.py' to use with 'pytest' framework

--HG--
rename : examples/mapsystem_test.py => PyDSTool/Generator/tests/test_mapsystem.py
Add dummy test for DDEsystem
Add 'Euler_ODEsystem' to basic ODE generators' tests
Refactoring: extract common vfield description
Rename and simplify a bit Oscillator forward integration test

--HG--
rename : PyDSTool/Generator/tests/test_samples.py => PyDSTool/Generator/tests/test_oscillator.py
Add cross tests for forward ODE integration
Fix path to data file
Add more FuncSpec tests
Drop sum for now, remove generated files
Fix failures on FreeBSD 11
Merge changes from 'develop' branch

--HG--
rename : PyDSTool/Generator/tests/test_samples.py => PyDSTool/Generator/tests/test_oscillator.py