Backlog/112 alarms

Adds an Alarm document, finishing the issue https://github.com/telefonicaid/fiware-connectors/issues/112

It also adds new INFO traces needed by the alarm system.

A minor fix in the README has been done as well.
The "For each configured Cygnus component (e.g. source handlers and sinks)" fragment could be ambiotus... I'd suggest to "fix" it with the number and name of the actual component at the present moment. E.g.:

"For each configured Cygnus component (the REST source handler and each one of the conifgured sinks -MySQL, CKAN, HDFS)"

Makes sense?