separate out attribute-rewrite code in FastArchivalUrlReplayParseEventHandler and make it customizable.
  added AttributeRewriter interface
  added StandardAttributeRewriter class
  addresses ARI-3810.
use AttributeRewriter for rewriting SCRIPT/@SRC for less surprises.
remove now unused anchorUrlTrans and jsUrlTrans in FastArchivalUrlReplayParseEventHandler.
Merge branch 'refs/heads/topic/custom-attr-rewrite' into ait-qa