resolving a release snag and removing profile conditions from top level of the build

* all modules must be built by default, including assembly and platform modelers.
  This ensures maven-release-plugin can bump their versions during release.
* Modeler platform builds within modules should be activated by explicitl profile (as before).
* Assemblies creation should be acrtivated by "assembly" profile (as before)
* adding a provided dependency on a cross-platform stub for eawt classes, so that MAc
  extensions can be compiled on Linux and Windows