Lectern

Feature

* Support overlays ([`518f3c9`](https://github.com/mcbeet/lectern/commit/518f3c993046fef9f9c35cb7e8fa7d23757ff949))

Feature

* Apply directives to context directly ([`a4cbf48`](https://github.com/mcbeet/lectern/commit/a4cbf48639fb553f2897adec049f47038d651b9c))

Fix

* Don't emit fallback function if there are fragments ([`57c8c0f`](https://github.com/mcbeet/lectern/commit/57c8c0f2397a5723a5baa969475dc0f9e25bd48e))

Feature

* Shorthand ([`6717332`](https://github.com/mcbeet/lectern/commit/6717332d9facf92f3d58c8e6c62d2b58712c96a0))

Feature
* Add merge_zip directive ([`add74f2`](https://github.com/mcbeet/lectern/commit/add74f2f8b223b29f2270de3aec5205ff217944d))

Feature
* Make it possible to raise an error if there was nothing in the message ([`165330e`](https://github.com/mcbeet/lectern/commit/165330e29e490860107d2755f09a0aa3f9d9c03a))