URL manipulation

# testing of URL manipulation:

base url (absolute)

comparison uri (absolute)

resolved url

##### note: results from "resolve" are placed in "comparison uri" edit field

### notes for testing

different types of uris:

- about:
- about:blank
- mailbox://nsmail-2.mcom.com/xxx
- mailto:brade@netscape.com)
- junk
- http://foo/
- http://foo.com/
- https://foo.com/
- ftp://ftp.mozilla.org/
- http://foo.com:8080/
- http://brade@foo.com/
- http://brade:password@foo.com/
- http://brade:@foo.com:8080/
- file:///
- file:///Quest/Desktop%20Folder/test.html

other variations:

- sub-directories on above list
- files on above list
- sub-directories and files on above list
- directories which don't end in a '/'
- files with queries
- files with no extension
- files with references
- files with params
- other schemes (chrome, ldap, news, finger, etc.)

This should be true:
resultString = baseURL.getRelativeSpec(URL);
<==>
baseURL.resolve(resultString) == URL.spec;