More control of monitor sensitivity

We have added a new monitor sensitvity option.

Now you can configure how sensitive our monitoring is when detecting issues.

Previously the only control available was a double knock feature which caused the system to double check any error one minute later before delaring a service as down.

We now have 3 sensitivity opitions:-

High - If the majority of monitoring servers (2 out of 3) detect an issue the service is declared down.

Normal - All 3 monitoring servers have to detact an issue before the service is declared as down.

Low - All 3 monitoring servers have to detact an issue and a second visit (double knock) is performed a minute later to confirm the issue before the service is declared as down.