* Added `embed_data_files` flag. (not yet used)
* Shared no longer exports `findDataFile`.
* `readDataFile` now returns a strict bytestring.
* Shared now exports `readDataFileUTF8` which returns a string like
the old `readDataFile`.
* Rewrote modules to use new data file functions and to avoid
using functions from Paths_pandoc directly.
- Removed writerLiterateHaskell from WriterOptions.
- Removed readerLiterateHaskell from ReaderOptions.
- Added Ext_literate_haskell to Extensions. Test for this
instead of the above.
- Removed failUnlessLHS from Shared.
Note: At this point, +lhs and .lhs extension no longer has any effect.
Need to fix.
