important bug fixes for ipython/jupyter
CHANGES:
- fixed rare bug when 'return' is non-integer in remote CK access (such as during crowd-tuning and crowd-testing)
- fixed copying to clipboard on Windows
- fixed init.py when using CK from scripts/ipython/jupyter (calling init())
- added ck.jerr(r) - print error with raise KeyboardInterrupt for Jupyter Notebooks
- fixed major problem with using CK without CK_ROOT env, i.e. from python scripts or Jupyter Notebooks
- fixed minor problem with CK_ROOT env (when is not set but can be detected automatically)
- added run_and_get_stdout function and fixed various problems with crowdtuning on MacOS