[AppDB] new screenshot and image classes

[Jonathan Ernst]

Hi Chris,

What I wanted to tell you on the channel was to discard the patch named:

[AppDb] screenshot and image class

Because we discussed it with Paul and I was able to make a new one using
his image class code and I used these classes everywhere on the code.

The new screenshot code is much better. We'll have to make a script to
go trough every old screenshot and create the thumbnails. Before I do
the script, please check if the watermarking is nice enough or if we
want another logo.

The name of the mail containing the new screenshot code is:

[AppDB] new screenshot and image classes

It is required to create the thumbnails subdirectories in order for the
scripts to work.

- data/screenshots/thumbnails/
- data/queued/screenshots/thumbnails/

See you.