Remove unnecessary Maven dependency

From a mail:

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Hi,

Having seen some of the cxx-code I would like to change an aspect which is in the
way of some users and in my way too: [parts of] the Implementation of the plugin is nailed to maven
in a way which is absolutely not necessary. The code depends on "MavenProject" and as far as I can see it is used for:
a) Getting the paths to the sources to analyze
b) Getting the location of the reports

I have a strong feeling that:

• For "a" we should just reuse the standard infrastructure already provided by sonar
• For "b" we should just use properties of "Project", which are already abstracted from the used runner.

That way we would get following advantages:

• Ability to use other runners (sonar-runner, ant, maybe others...)
• Simplified code
• Less deprecated API calls
• Less open Jira issues
• More standard cxx-project pom

This is not a refactoring, though, and would require to change the "old" pom's; in detail:

• morph "<configuration><sourceDirs>..." to "<build><sourceDirectory>..."
• introduce new properties for "b" and move according values (if any).
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To test just run the analysis with sonar-runner or the ant tester. The former has, the latter has been not tested before commit.