Add hints for how to build
Fix eclipse m2e detection

Thank you @ctrueden for mentioning this on #5.
Add version for maven-eclipse-plugin

Was probably managed once by the old parent pom.
Add finalName tag to maven-bundle-plugin
Merge maven profiles build-bundle and importable-projects

Since we use m2e (Maven Eclipse Integration), we do not need to
generate projects. This solution also fixes some of the problems
with the groovy script (See #5).

This commit was strongly inspired by the work of @hornm and @dscho on the
wip branch of this repository (which may have been removed by the time you
read this commit message).
Add eclipse m2e lifecycle mappings

For better comatability with m2e. Up till now some plugins were ignored by
default. Thank you @dscho for pointing out how to do this in #5 !

The configuration of <action> is still preliminary and very likely will be
changed in future commits.