register ignores configure's --interfacedir

[awick@…]

Create a little fake library directory (I made .../Setup.lhs, .../testpkg.cabal, and .../TestPkg/Foo.hs).

ghc --make Setup.lhs -o setup -package Cabal
./setup configure --interfacedir=/
./setup register
cat dist/installed-pkg-config 

This should result in a line saying

haddock-interfaces: /TestPkg.haddock

but actually generates

haddock-interfaces: /usr/local/share/doc/TestPkg-1.0.0/html/TestPkg.haddock

[guest]

This is under GHC 6.8.1; I didn't notice that option.

[duncan]

Fix in Cabal HEAD. We can push this one to the 1.2 branch too.