Display warning when consuming jars from the libs folder of apklib & aar

Initial conversation here: https://github.com/jayway/maven-android-plugin/commit/249ad1e1eac052c3f1db6bd4c9270c9fb25c0cec#diff-2


Currently this only deactivate apklib libs\jars and consume the aar libs.

I still need to enable the pom flags in some way.

- DO NOT MERGE yet