Allow .deb builds with Java7

git-svn-id: http://svn.igniterealtime.org/svn/repos/openfire/trunk@13993 b35dd754-fafc-0310-a699-88a17e54d16e
Fix typo in Makefile target: s/dbkg/dpkg/

git-svn-id: http://svn.igniterealtime.org/svn/repos/openfire/trunk@13994 b35dd754-fafc-0310-a699-88a17e54d16e
Fix broken codePoint check (OF-391)

char in java is 16-bit. Therefore checking for anything greater then
0xFFFF makes no sense. We want to know here if the character is maybe
part of a surrogate pair, that's why 'is(High|Low)Surrogate(char)' is
now used.

git-svn-id: http://svn.igniterealtime.org/svn/repos/openfire/trunk@13995 b35dd754-fafc-0310-a699-88a17e54d16e
Make illegal characters detection even more strict

The previous implementation allowed for high surrogates followed by
non-low surrogates. We now assure that every high surrogate is followed
by a low surrogate (under the assumption that the last byte in an XMPP
stream can not be a unicode surrogate pair).