Moved old tests into Old.hs and added new simple test-pandoc.hs for
loading and grouping together tests from different files. Later
commits will add more testfiles to the suite with more modular tests.
+ You can now specify glob patterns after 'cabal test';
e.g. 'cabal test latex' will only run the latex tests.
+ Instead of detecting highlighting support in Setup.hs,
we now detect it in test-pandoc, by looking to see if
'languages' is null.
+ We now verify the lhs readers against the lhs-test.native,
normalizing with 'normalize'. This makes more sense than
verifying against HTML, which also brings in the HTML writer.
+ Added lhsn-test.nohl.{html,html+lhs}, so we can do the lhs
tests whether or not highlighting has been installed.
