Add a convenient assess lists equivalence.
Add convenient method to extract specific values from a map.
[maven-release-plugin] prepare release collection-1.8
[maven-release-plugin] prepare for next development iteration
Add a composed key able to deal properly with heterogeneous types.

To use such object with a reasonable additional work, we have used
a feature of Java 1.7 (implicit parameters with "<>"), so this code
is not available for Java 1.6.