Remove spurious resurrection of src/swing.
Pull filter-pom out from deploy-one.
Prepare maven-based distribution building.

The idea is that a Scala distribution is a simple
repackaging of artifacts already available on maven.

Already available: typical jars for the artifacts (classes, sources, scaladoc).
To add: the bin/, doc/, and man/ directories.

Thus, move the contents that should end up in the distribution
from docs/ to doc/, create the man/ directory with the manpages,
and include the scripts in bin/.

Next up: package these directories in a jar and publish to maven,
with a dependency on scala-library-all, scala-reflect and scala-compiler,
for the jars that should end up in the distribution.
Rename maven-base to dist.maven.

Set the property in the init target.
pack-maven.dist