In Remarkup, prevent "%%%" on a line from self-terminating the literal block
Fixes T12621. Currently, %%% on a line by itself can both start and terminate a literal block. This is silly and presumably not what anyone ever intends.
Instead, if %%% started a block, don't let it terminate the block.
- Added a failing test.
- Made it pass.
Reviewed By: chad
Maniphest Tasks: T12621
Differential Revision: https://secure.phabricator.com/D17772