Add a skip parameter to the preprocess goal

[htfv]

Many Maven plugins have a skip parameter with an associated property to skip the execution. Having such parameter and property is convenient as it allows a) temporarily disabling plugin in command line by adding a -D option; b) configuring plugin in a parent POM and redefining a property in a child POM to change behavior (enable or disable execution).

Please add such parameter to the JCP Maven plugin.

I can create a pull request if it helps.

[raydac]

I have added boolean skip parameter which also can be set through property -Djcp.preprocess.skip=true
to skip execution of plugin, just add

<skip>true</skip>

[htfv]

I tested it and it works. Thank you for quick response.