Moved file_transfer_auto_accept setting to global

darcs-hash:20081128150920-58252-204281af75a9db2e5eebd8034200b34d8ce58511
do not always use text/plain in sip_im_send_file.py

darcs-hash:20081128151934-b2873-e517795a03cdd0254f8ed6002dcbb510a58352fa