cabal init patches

Hi all, I've finally gotten around to working on some improvements to cabal init. The first three listed patches are minor improvements. The last is a bigger addition, which tries to guess the right package dependencies to list in the build-depends field. Feedback welcome. -Brent 4 patches for repository http://darcs.haskell.org/cabal: Fri Oct 14 16:21:34 EDT 2011 Brent Yorgey * init: improve prompt: 'homepage' field is not for repos. Fri Oct 14 16:22:10 EDT 2011 Brent Yorgey * init: improve prompt: enclose y/n in parens Fri Oct 14 16:22:30 EDT 2011 Brent Yorgey * init: see whether source directory 'src' exists. Tue Oct 25 01:09:00 EDT 2011 Brent Yorgey * init: guess at filling in deps in the build-depends: field