buildLocalCabal: allow cabalDrvArgs in buildLocalCabalWithArgs

allows to write neat expressions like (as we're still generating an
expression string):

```
{
  build = haskellPackages.buildLocalCabalWithArgs {
    inherit src name;
    cabalDrvArgs = {
      jailbreak = false;
      doCheck = false;
    };
  };
}
```

without resorting to weird kung-fu like darcs does:

```
darcs = haskellPackages.darcs.override {
  # A variant of the Darcs derivation that containts only the
  # executable and
  # thus has no dependencies on other Haskell packages.
  cabal = { mkDerivation = x: rec { final = haskellPackages.cabal.mkDerivation (self: (x final) // {
            isLibrary = false;
            configureFlags = "-f-library"; }); }.final;
          };
};
```

While here, move the `jailbreak = true;` as the default `cabalDrvArgs`
option.
Merge branch 'buildLocalCabal-drvArgs' of git://github.com/proger/nixpkgs

buildLocalCabal: allow drvArgs in buildLocalCabalWithArgs