Add option for user to enable or disable debug reporting

[GaurangTandon]

The number of CRLErrors that can be reported by pre.js in the console can be quite high, and users won't like their console filled with them. However, they are useful for profiling what went wrong.

Consider adding a checkbox option in settings to show logs.
Moreover, add a reminder in all those alert boxes to check that box before sending logs via email.

[GaurangTandon]

These CRLErrors have been considerably reduced since that day. Now they only occur once per every ctx menu snippet insertion.

However, I do like the idea of having a "debug mode" and would want to consider that later.