canonical_iface_uri expands "alias:prog" to the URI in the 0alias script
canonical_iface_uri expands "alias:prog" to the URI in the 0alias script

For example:

  $ 0launch --before=2.7 alias:rox

is short for:

  $ 0launch --before=2.7 `0alias -r rox`

0install/0install,dabrahams/0install,bhilton/0install,pombreda/0install,fdopen/0install,fdopen/0install,jaychoo/0install,jaychoo/0install,timdiels/zeroinstall,timdiels/0install,timdiels/zeroinstall,michel-slm/0install,fdopen/0install,afb/0install,gasche/0install,dbenamy/0install,0install/0install,bhilton/0install,HoMeCracKeR/0install,HoMeCracKeR/0install,bastianeicher/0install,gfxmonk/0install,dabrahams/zeroinstall,timdiels/0install,gfxmonk/0install,bhilton/0install,DarkGreising/0install,timdiels/0install,timdiels/0install,timdiels/zeroinstall,dabrahams/0install,dabrahams/zeroinstall,gasche/0install,michel-slm/0install,pombreda/0install,bartbes/0install,bastianeicher/0install,gfxmonk/0install,afb/0install,dbenamy/0install,DarkGreising/0install,gasche/0install,dabrahams/0install,afb/0install,dabrahams/zeroinstall,bastianeicher/0install,pombreda/0install,bartbes/0install,jaychoo/0install,michel-slm/0install,0install/0install,DarkGreising/0install,gasche/0install,HoMeCracKeR/0install,afb/0install,dbenamy/0install,bartbes/0install