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.
