8000941: Remove ftp from the required list of protocol handlers

[Alan Bateman]

Earlier this week I brought up the suggestion to drop ftp from the list 
of protocol handler guaranteed to be present [1]. Here's the webrev with 
the proposed changes:

http://cr.openjdk.java.net/~alanb/8000941/webrev/

The only change to normative text is in the URL, the only changes are 
non-normative.

-Alan

[1] http://mail.openjdk.java.net/pipermail/net-dev/2012-October/004970.html