interesting, seems the "breaking barriers" openwrt repo works ok on 1.5.3 "attitude adjustment"
just following another thread to upgrade mqtt for tls/ssl
http://forum.arduino.cc/index.php?topic=370299.0
uninstall all mosquitto stuff
(flipping yun wget version ssl problems so have to manual download, but maybe bb repo wget fixes that???)
download on host pc
then scp them to yun and use opkg install to install from the files...
cool.... works OK using non tls/ssl socket with default config.... not been through the extensive rigmarole of ssl certificates and where and what type etc. yet....