Fix the hex2bin function.  PHP 5.4.0 has this, but having our own ensures things will still work.  Fix the announce so it uses the hash to find the peer rather than the id itself which works, but it's easier to maintain using regular coding.

git-svn-id: https://svn.code.sf.net/p/freeghost/code/trunk@2223 71f96598-fa45-0410-b640-bcd6f8691b32
Merge svn with master