talkatu/talkatu

Make it so that talkatu.h may only be included outside of the Talkatu build.

Testing Done:
Compile only.

Reviewed at https://reviews.imfreedom.org/r/233/
# Talkatu
![logo](logo.png)
[ ![Issues](https://img.shields.io/badge/Issues-YouTrack-ee3b8b.svg) ](https://issues.imfreedom.org/issues/TALKATU)
Talkatu is a collection of Gtk+ widgets that are useful for chat applications.
It was started as a rewrite of the GtkIMHTML widget found in Pidgin, but
quickly expanded to include most things related to conversation windows.
This is highly experimental right now and might eat babies, we're not sure
yet. So proceed with caution :-D
## Name
The name is a pun of talkatoo from Super Mario Odyssey which just so happens
to also say "talk at u" :-D
## Dependencies
Currently Talkatu depends on
* glib-2.0 >= 2.40.0
* gtk+-3.0 >= 3.10.0
* gladeui-2.0 >= 3.0.0
* gspell-1 >= 1.2
* gumbo >= 0.10
* libcmark
## Internationalization
All of our internationalization work is done via the
[Talkatu](https://www.transifex.com/pidgin/talkatu/dashboard/) project under
the [Pidgin organization](https://www.transifex.com/pidgin/) on
[Transifex](https://www.transifex.com). If you would like to contribute
that's the place to do it.