Don't use hpp as the preprocessor on Windows.

[TravisWhitaker]

Building master on Windows with GHC 8.2.1 yields this on my Windows 10 machine:

C:\Users\Travis\sources\GLUtil\src\Graphics\GLUtil\ShaderProgram.hs:1:1: error:
    File name does not match module name:
    Saw: `Main'
    Expected: `Graphics.GLUtil.ShaderProgram'
  |
1 | {-# LANGUAGE CPP #-}
  | ^

--  While building package GLUtil-0.9.1.1 using:
      C:\sr\setup-exe-cache\x86_64-windows\Cabal-simple_Z6RU0evB_2.0.0.2_ghc-8.2.1.exe --builddir=.stack-work\dist\e53504d9 build lib:GLUtil --ghc-options " -ddump-hi -ddump-to-file"
    Process exited with code: ExitFailure 1

The issue seems to be due to hpp. I'd be happy to help figure out what's going on with hpp on Windows (I don't have this problem on my Linux machines), but in the meantime using cpphs on Windows makes the package buildable.

[TravisWhitaker]

Should fix #25.

[acowley]

Thank you, I’ll push to hackage asap!

[TravisWhitaker]

Thanks for the speedy response.

Any chance of getting this package back in the Stackage snapshots? It was last in nightly-2015-12-14.