Request for Review: Fix sed expression in compare-images target

[Magnus Ihse Bursie]

The Release Engineering team in Oracle encountered a problem when 
building in a path that contained the character "@". Normally, having 
strange names in the directory where you are building is not a good 
idea, but in this case the path was created by the Hudson CI system.

The problem is a single sed expression, basically "sed -s at ...@..@". I 
changed this to "sed -s|...|...|", a character that is much less likely 
to actually appear in a filename.

Webrev here:

http://cr.openjdk.java.net/~ihse/fix-compare-image-sed/webrev.00/

Kelly, if this is accepted by reviewers, can you create a bug and push this?

/Magnus