Added Macros and Pattern for easy Haskell packaging

[DataDrake]

These macros should make it considerably faster/easier to package Haskell libraries and development binaries:

• cabal_configure Create a user package database, rebuild the 'package.cache' for ghc, then configure for a dynamically linked build
• cabal_build Compile the source with %JOBS% processes
• cabal_install Install the outputs to $installdir
• cabal_register Generate the package.conf.d entry and install it

A pattern was also added to move the static libs into a -devel sub-package

Caveat You must always install ghc and haskell-cabal-install for the macros to work.

[ikeydoherty]

Indentation in rc.yml is bork but I'll fix post-merge ty