RFR: JDK-8213227: Update jib src excludes to filter webrev and Jreg directories

[Erik Joelsson]

This patch adds some useful excludes for jib source bundle creation, 
which will help avoid sending in too much junk in Mach 5 jobs.

The strings are rewritten as arrays, which are now supported, as well as 
using ** globs to match arbitrary directory depths. I've also removed 
the no longer used .build dir from excludes.

http://cr.openjdk.java.net/~erikj/8213227/webrev.01/

Bug: https://bugs.openjdk.java.net/browse/JDK-8213227

/Erik