Create new pynapl instance from Dyalog stuck hangs infinite loop if Py.dyalog fixed with wrong slashes

[rikedyp]

      2⎕fix'C:\Users\rpark\Documents\GitHub\pynapl\pynapl/Py.Dyalog'
      py←⎕new Py.Py
...

Most of that path uses Windows OS-appropriate backslashes, but the final slash is forward. However Pynapl is getting the path to its files it ends up one level too high in this case.

• Resolving pynapl path should normalise for any slashes
• Attempts to connect to python instance from Dyalog should have a retry limit and fail with a useful error about the inability to connect (with whatever information might be relevant / available e.g. python exe path, arguments that were given to python process, python process ID etc).