haskell-packages: make hoogle wrapper much more helpful

* Build most of the stuff on /tmp, not in /nix/store.
* Generate hoogle database for all the dependencies.
* Generate haddock index and contents files.
* Cleanup.

pkgs/development/haskell-modules/hoogle-local-wrapper.sh

@@ -2,5 +2,4 @@
 
 COMMAND=$1
 shift
-HOOGLE_DOC_PATH=@out@/share/hoogle/doc exec @hoogle@/bin/hoogle \
-    "$COMMAND" -d @out@/share/hoogle "$@"
+exec @hoogle@/bin/hoogle "$COMMAND" -d @out@/share/doc/hoogle "$@"