Remove m2e connectors from central

m2e changed major version to 2.0 and breaks almost all m2e connectors we propose in central.

here the proposition list :

m2e-apt -> migrate to new connector release with m2e 

m2e-tycho -> propose to remove as https://github.com/eclipse-m2e/m2e-core/issues/605

m2e-buildhelper -> propose to remove as https://github.com/eclipse-m2e/m2e-core/issues/885

m2e-egit -> propose to remove

m2e-wro4j -> try to migrate as we own the repo https://github.com/jbosstools/m2e-wro4j/