Sort plugins in composer.json in alphabetical order

It is easier to keep track of them this way.
Update existing plugins
Add new plugins
Update the kyte theme using a manual version

I had problems making composer pick up changes in the remote repo via a
“dev-master” version specification, so I moved to manual versioning.
The theme’s version is 1.1.19. Adding a “.1” at the end means we’ve made
changes in one revision to 1.1.19-base.

Fixes #7.