Resolve problem with java downloading

Java download is often fails with broken connection to java oracle.

Way to resolve this problem:
* Prepare slave for diskimage jobs with pre-downloaded java tarball
* Setup simple http server for java downloading
* Use link for java downloading from localhost

Main parameter for java elements is JAVA_DOWNLOAD_URL, and if it is set,
you can't use parameter JAVA_FILE. So, we hack JAVA_DOWNLOAD_URL in that way.

Change-Id: I520a4dd0aa9efec82574e5080f066700a21ed16f
Merge "Resolve problem with java downloading"