updated to use m2e 1.4 maven execution context

Signed-off-by: Igor Fedorenko <igor@ifedorenko.com>
Reintroduced explicit support for modello-upgrade-plugin

As of version 1.1, modello-upgrade-plugin does not properly participate
in m2e workspace build. Added special project configurator and
build participant to compensate.

Signed-off-by: Igor Fedorenko <igor@ifedorenko.com>
fixed build failures on osx with oracle java 7

Signed-off-by: Igor Fedorenko <igor@ifedorenko.com>