Solve/workaround the issue of needing endorsed libraries on Java 6

In case endorsed directories are defined in the maven-compiler-plugin configuration, this new maven configurator : parses <compilerArgument> for -Djava.endorsed.dirs=( [^ \\t] +) and falls back on the <compilerArguments><endorseddirs> value. lists all the jars and zips found under the endorsed directories and adds them to a new Endorsed Libraries classpath library. Endorsed Libraries is put first on the project's classpath. For now the endorsed dirs need to have been created/populated before the project's configuration. During project configuration, if the endorsed directories are missing, an Error Marker is added at the maven-compiler-plugin location in pom.xml. If there's a maven-dependency-plugin:copy goal defined in a plugin execution, then a quick fix will be available for the error marker, basically proposing the user to run mvn <phase_executing_dependency_copy>. After that goal is run, the project configuration is updated, effectively adding the Endorsed Libraries to the project's classpath. Please note that the maven-dependency-plugin execution is still not covered by m2e (this goes beyond the scope of this JIRA), thus requires custom lifecycle mapping (see http://wiki.eclipse.org/M2E_plugin_execution_not_covered )