Kie server: add war assemblies and move integ. tests into own module

@etirelli @mrietveld please review the changes and let me know if there is anything I could fix/enhance.
@psiroky We want to work towards less config in the future: -1 for extra config for Jackson 2.x. +0 for config for Jackson 1.x if it means that we have less config for Jackson 2.x.