untangle ftp protocol from general networking URL tests

Given the recent downgrade of the ftp handler by 8000941: "Remove ftp from the required list of protocol handlers", the networking regression tests should be able to run, and pass, without the ftp handler. This will make testing the smallest profile and the base module easier.

There are several tests exercising URL and URI parsing, that amongst others, use the ftp protocol. These tests should check if the runtime supports ftp before creating ftp URLs. Specific tests for ftp live in directories like, test/sun/net/ftp and test/sun/net/www/protocol/ftp, and are straight-forward to exclude as not-applicable directories. These tests will no be changed ( as part of this JIRA issue ).