Added link ends to role documentation.
Sorted the language options list alphabetically, and added missing options.
Prevent line wrapping after the dash of an option.
Added more option implication documentation.
Merge branch 'master' of git://git.haskell.org/ghc

Conflicts:
	docs/users_guide/flags.xml
Make DeriveTraversable imply DeriveFunctor/Foldable

Implements #9069
Added testcase for #9069
Update mod73 test output

to what I observe on travis and on my validate machine, even though my
local tree produces the previous output.
Use UnicodeSyntax when printing

When printing Haskell source, and UnicodeSyntax is enabled, use the
unicode sytax characters (#8959).