Runtime filtering

Filters based on the new runtimes property in SBTEnvironment.

Reorganised all of the JS samples. Changed their properties.

Ran all tests and they haven't been broken. 

@markewallace @priand This took so long because the tests failed to execute properly on jenkins server for some reason, and it then took ~2.5 hours to run them locally instead... I expected it to be done much sooner.