Only collect remote coverage data when running in coverage mode

Story:

In order to be more efficient
As a Tester
I want to only collect remote coverage data when collecting local coverage data

Scenario:

Given that I have the Jacoco Extension on client classpath
When the client JVM is running in Coverage Mode
Then the Jacoco Extension should instrument the Deplomyent classes to collect remote coverage

Given that I have the Jacoco Extension on classpath
When the client JVM is not running in Coverage Mode
Then the Jacoco Extension should do nothing

Rationale:

The Jacoco Extension will start recording remote coverage data when it's on classpath. As long as there is no one around to process the coverage data, that being a Maven Report plugin or a Eclipse IDE plugin, collecting the remote data is pointless.