Merge pull request #97 from gwils/gitignore-cabal-sandbox-newbuild

gitignore cabal sandbox and new-build artifacts

.gitignore

 # Specific generated files
 GNUmakefile
 autom4te.cache/
+.cabal-sandbox/
+cabal.project.local
+cabal.sandbox.config
 config.log
 config.status
 configure
 dist/
 dist-install/
 dist-newstyle/
+.ghc.environment.*
 ghc.mk
 include/HsUnixConfig.h
 include/HsUnixConfig.h.in