Minimal update with new repo URLs & build instructions

src/runtime/haskell/pgf.cabal

@@ -8,7 +8,7 @@ category: Natural Language Processing
 synopsis: Grammatical Framework
 description: A library for interpreting the Portable Grammar Format (PGF)
 homepage: http://www.grammaticalframework.org/
-bug-reports: https://github.com/GrammaticalFramework/GF/issues
+bug-reports: https://github.com/GrammaticalFramework/gf-core/issues
 maintainer: Thomas Hallgren
 tested-with: GHC==7.6.3, GHC==7.8.3, GHC==7.10.3, GHC==8.0.2
 
@@ -45,9 +45,9 @@ Library
 --if impl(ghc>=7.8)
 --  ghc-options: +RTS -A20M -RTS
   ghc-prof-options: -fprof-auto
-  extensions: 
+  extensions:
 
-  exposed-modules: 
+  exposed-modules:
     PGF
     PGF.Internal
     PGF.Haskell