Add 4 features to maven management :
    * Retrieve maven properties from help:effective-pom
    * Extract targets path from maven properties
    * Recursively search pom file in parents (using findfile)
    * Use a dictionary to cache classpath for each project pom
correct test directory property name
re-add pom timestamp management
Merge pull request #712 from jvenant/master

Maven manage improvement proposition
Merge branch 'master' into gcc_refactor