Patch by Michael Glavassevich

The patch fixes Bugzilla #19787, #20006, #20009, #20010 and #20287, and
several other issues. A summary of the changes is listed below:

1. Added '[' and ']' to reserved characters as per RFC 2732.
2. '[' and ']' added in RFC 2732, are not allowed in path segments, but
may appear in the opaque part.
3. No URI can begin with a ':'.
4. URI has no scheme if ':' occurs in a URI after '?' or '#', it's part of
the query string or fragment.
5. Whitespace (even escaped as %20) is not permitted in the authority
portion of a URI.
6. IPv4 addresses must match 1*3DIGIT "." 1*3DIGIT "." 1*3DIGIT "."
1*3DIGIT. Since RFC 2732.
7. IPv4 addresses are 32-bit, therefore no segment may be larger than 255.
This isn't expressed by the grammar.
8. Hostnames cannot end with a '-'.
9. Labels in a hostname must be 63 bytes or less [RFC 1034].
10. Hostnames may be no longer than 255 bytes [RFC 1034]. (That
restriction was already there. I just moved it inwards.
11. Added support for IPv6 references added in RFC 2732. URIs such as
http://[::ffff:1.2.3.4] are valid. The BNF in RFC 2373 isn't correct. IPv6
addresses are read according to section 2.2 of RFC 2373.


git-svn-id: https://svn.apache.org/repos/asf/xerces/c/trunk@175124 13f79535-47bb-0310-9956-ffa450edef68