Electron: Chrome disconnects if Node exits.

[jgarzagu]

Currently if there is an error, like opening a wrong serial port, node exits. The problem is that when using it with chrome, chrome stops working which can make it hard to debug the program. See image below:

A solution to this could be to halt instead of exit or add some code to choose whether to halt or exit.

[jgarzagu]

Also set a debug mode (ex. just print on text the data sent to the baord)