Renamed some tests, introducing subsidiary directories
for fb2, docx, epub.
Cleaned up tests in cabal file.
Combined dokuwiki-writer and dokuwiki_inline_formatting tests.
This will make paragraphs styled with `Author`, `Title`, `Subtitle`,
`Date`, and `Abstract` into pandoc metavalues, rather than text. The
implementation only takes those elements from the beginning of the
document (ignoring empty paragraphs).
Multiple paragraphs in the `Author` style will be made into a metaList,
one paragraph per item. Hard linebreaks (shift-return) in the paragraph
will be maintained, and can be used for institution, email, etc.
