EPUB test renaming.

Renamed epub test files so they're identified more clearly as
epub:  features.{epub,native} -> epub.features.{epub,native},
and similarly with formatting.{epub,native}.

Added epub test files to cabal file, so they'll be included in
the tarball.

pandoc.cabal

@@ -158,6 +158,8 @@ Extra-Source-Files:
                  tests/lhs-test.html+lhs,
                  tests/lhs-test.fragment.html+lhs,
                  tests/pipe-tables.txt,
+                 tests/epub.formatting.epub,
+                 tests/epub.features.epub,
                  tests/fb2.basic.markdown,
                  tests/fb2.basic.fb2,
                  tests/fb2.titles.markdown,

tests/Tests/Old.hs

@@ -147,9 +147,9 @@ tests = [ testGroup "markdown"
               "txt2tags.t2t" "txt2tags.native" ]
         , testGroup "epub" [
             test "features" ["-r", "epub", "-w", "native"]
-              "features.epub" "features.native"
+              "epub.features.epub" "epub.features.native"
           , test "formatting" ["-r", "epub", "-w", "native"]
-              "formatting.epub" "formatting.native"
+              "epub.formatting.epub" "epub.formatting.native"
           ]
         , testGroup "other writers" $ map (\f -> testGroup f $ writerTests f)
           [ "opendocument" , "context" , "texinfo", "icml"