Better release management

[gevegab]

Currently the release process is complicated by several factors:

• the parent pom of the is in a subdirectory
• the apam maven plugin is at the same time built and used by the project
• test projects are not included in the release, but are inside the file hierarchy
• some distributions and demos are not included in the release

this causes several problems that make the release process complicated. We need to find a better
project layout to separate the different inter-related sub-projects, but allow a unified release