These changes makes sure cabal2arch uses the modified API of archlinux (see the related pull request archhaskell/archlinux#6). They also add a new command line flag so configure flags can be passed in at the call (only when converting one Cabal file though).
I thought this would warrant a pull request since it modifies the output.
Dealing with flag assignments in modified preprocessCabal.
Getting the flags pushed through to the PKGBUILD. Bumping the version
since the output is modified.
Adding command line argument for configure flags.