ihaskell 0.4.0.0

add ihaskell 0.4.0.0

Because current ihaskell-0.3.0.4 is incompatible with aeson at current build. The cause is similar to https://github.com/snapframework/snap/issues/90.

The ebuid is mostly generated by `hackport merge', a line
~~~
       >=dev-lang/ghc-7.6:=[profile?] <dev-lang/ghc-7.7:=[profile?]
~~~
in RDEPEND is removed, because it refers to ghc-7.7 which causes error in emerge.

mono-traversable-0.6.0 is pulled by ihaskell 0.4.0.0.

However there are some issues to solve:

1. It requires ipython >= 2.0.0 to run which is not in portage and this requirement is not in ebuild.
2. The ipython profiles
~~~
/usr/share/ihaskell-0.4.0.0/ghc-7.6.3/profile/profile.tar
~~~
generated after emerge is broken( The file in cabal source tarball is OK). This may be in bug in haskell-cabal.eclass.