Improved error handling and logging

[petargyurov]

Feature
Currently not all errors are handled. We need a robust system that 1) notifies the user of any errors 2) logs detailed error information to a file

Additional Detail
Some errors are already handled, but there isn't much handling of errors coming from the backend process, especially during initiating of the child process.

[petargyurov]

The current implemenation is not as robust or as comprehensive as it should be but we have:

• handling local JS errors
• handling backend errors
• handling stdout and stderr streams from the backend
• logging everything to a log file

There is one (maybe two?) major unhandled cases:

• remote code errors (i.e.: errors in libraries)
  • these cannot be read by JS because of a Chromium CORS security settings (see Unable to handle remote script errors #15)
• Electron errors in the main process
  • have not put in the time to implement this

I was really hoping that Electron would just have a global error handler that receives a callback but there doesn't seem to be such a feature. On top of that, not all JS errors trigger the typical error event handler... 😡

Bottom line is, there is still major room for improvement on this front. One thing that we need to seriously consider is the recycling of the log file. Right now it will grow in size until a new install (?) erases it.