RFR (round 2): JDK-8048150: Allow easy configurations for large CDS archives

[Calvin Cheung]

Based on review comment, I've re-implemented the fix with only one vm 
option to handle both "large" and "huge" shared archive size:

     -XX:SharedArchiveSize=[large|huge]

webrev:
     http://cr.openjdk.java.net/~ccheung/8048150/webrev/

thanks,
Calvin