Invalid Export-Package entries

[lrytz]

I'm on 2.13.x, but maybe it's the same on other branches

Our jars contain invalid entries in Export-Package, for example build/osgi/scala-library.jar/META-INF/MANIFEST.MF has

Export-Package:
  library.properties;version="2.13.0.v20170405-121540-pre-1981aeb-1981aeb"
  rootdoc.txt;version="2.13.0.v20170405-121540-pre-1981aeb-1981aeb"

Probably because of this, we get in build logs

[warn] bnd: Invalid package name: 'repl-jline.properties'
[warn] bnd: Invalid package name: 'scala-asm.properties'
[warn] bnd: Invalid package name: 'scala-buildcharacter.properties'

(https://scala-ci.typesafe.com/view/scala-2.13.x/job/scala-2.13.x-integrate-bootstrap/312/consoleFull)