add explicit conversion from Int to Id in anticipation of making said type opaque
add explicit conversion from Int to Id in anticipation of making said type opaque

Ignore-this: 1897c037a9b2a1dc55f474e943567027

darcs-hash:20090218160928-1a7c6-ed200066351890c2c2fe91e7bb8148e6e4dbf481

jimcrayne/jhc,jimcrayne/jhc,jimcrayne/jhc,jimcrayne/jhc