Limiting improves readability on wide monitors.

The immediate update of the settings is done by just exposing settings
as properties and then setting the settings as a context property.

Added an option to have descriptions for user settings.

Added an optional feature to show bigger emoji-only messages with 3 or less emoji

Update macOS building dependencies now that libolm is available in Homebrew.  Thanks @aaronraimist 

Signed-off-by: Aaron Raimist <aaron@raim.ist>

Implemented message background highlight feature as per issue #193

Fix nheko build(uses mtxclient device-verification)

Currently translated at 100.0% (277 of 277 strings)

Translation: Nheko/nheko
Translate-URL: http://weblate.nheko.im/projects/nheko/nheko-master/de/

(This is such a hack and will probably break, but it works for now for
most cases...)

In the future we should probably add a gradient when clipped...