PR #5884.
+ Use pandoc-types 1.20 and texmath 0.12.
+ Text is now used instead of String, with a few exceptions.
+ In the MediaBag module, some of the types using Strings
were switched to use FilePath instead (not Text).
+ In the Parsing module, new parsers `manyChar`, `many1Char`,
`manyTillChar`, `many1TillChar`, `many1Till`, `manyUntil`,
`mantyUntilChar` have been added: these are like their
unsuffixed counterparts but pack some or all of their output.
+ `glob` in Text.Pandoc.Class still takes String since it seems
to be intended as an interface to Glob, which uses strings.
It seems to be used only once in the package, in the EPUB writer,
so that is not hard to change.
Quite a few modules were missing copyright notices.
This commit adds copyright notices everywhere via haddock module
headers. The old license boilerplate comment is redundant with this and has
been removed.
Update copyright years to 2019.
Closes#4592.
The org reader test file had grown large, to the point that editor
performance was negatively affected in some cases. The tests are spread
over multiple submodules, and re-combined into a tasty TestTree in the
main org reader test file.
