[cleanup] cleanup pom before next release

* adjusted pom to maven code convention: http://maven.apache.org/developers/conventions/code.html
* introduced updated profile 'release', to release the scim-schema to maven central, without the load of the sonatype parent pom
* updated integration profile to snapshot profile
* updated developer to the OSIAM team dev
* changed release tag from scim-schema-{version} to v{version}, like the other OSIAM projects
yes, or I change the pom with this PR, because the next release is hopefully tomorrow. Or do you think this is to much (all-in-all) for a bug-fix release?