RFR: JDK-8200174 compare.sh improvements

Fri Mar 23 11:59:49 UTC 2018

This patch contains two larger improvements to compare.sh:
* Start by doing the binary comparison. This is often the most 
interesting part, and for interactive sessions, much time is saved is 
this is done first (after the quick sanity check of the file tree).
* Allow not all parts (like the JRE image and sec-bin.zip) to be 
present. This also speeds up tests by making "make jdk-image" as the 
prerequisite for running comparison.

A fix for the hex disasm filter on solstudio is also included.

Bug: https://bugs.openjdk.java.net/browse/JDK-8200174
WebRev: 
http://cr.openjdk.java.net/~ihse/JDK-8200174-compare-sh-improvements/webrev.01

/Magnus