Remove libjansson dependency

[fejfighter]

with the recent inclusion of a custom json parser in emacs we no longer need libjansson for fast json decoding

closes #16

[fejfighter]

@majjejjam this is what i meant

[majjejjam]

These commits add patches to the manifest that are not present in the repository, right? I also think emacs.desktop-exec-wrapper.patch needs for the command to be emacs-wrapper instead of emacs.

[fejfighter]

Thanks, good catch. I forgot to add them to the commit, I have fixed it.

I pulled the patches from the fluthub repo emacs. They have gone in on the dev-wrapper arrangement, which I didn't want to do. so I have pulled that back out.