RFR: 8276170: Create Sources when publishing to Maven

[eduardsdv]

Create sources.jars and attach they to the publish task, so that they can be uploaded to the (e.g. maven) repository automatically.

-------------

Commit messages:
 - 8276170: Remove trailing whitespaces
 - JDK-8276170: Create Sources when publishing to Maven

Changes: https://git.openjdk.java.net/jfx/pull/657/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jfx&pr=657&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8276170
  Stats: 13 lines in 1 file changed: 13 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jfx/pull/657.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/657/head:pull/657

PR: https://git.openjdk.java.net/jfx/pull/657