Clear all timers on exit (also in other places, to avoid errors when the terminal is closed before the window) and factorize window creation

Don't use event.reply when not replying to an event, use win.webContents.send, because this is what we actually do

This stuff is a backend stuff, the instance is just a viewer.

Refact config.js file, use dirrectly the object created from the ini file (less lines of code, less errors)

Wait for lektord to reply to pings for installing all callbacks, fix bug where lkt couldn't connect to lektord