* slaves now ask for /admin/streamlist.txt which serves a plaintext version of the source list (this is what it was expecting to get)
* /admin/streamlist still serves XML (which slave.c wasn't expecting)
* fixed a few cases of pointer invalidation due to possible config re-reading.
* slave relay now uses relay password to get the list of streams to relay

svn path=/trunk/icecast/; revision=5695