When running tasks, shell is invoked like:

   $THEIA_SHELL -c "command with arguments that\ can\ contain\ spaces"

so that frontend requests are requested as theia computer partition.
Practically this means that if theia is installed on slapos master,
frontend requests for slapos inside theia partition will be requested as
this theia instance.

This disable a theia security feature of using a different hostname for
each webview. By defaut, for each webview, thiea generate an unique
hostname that when using vifib frontends would be something like
https://uuid.webview.softinstXXX.host.vifib.net but that's not usable in
our case because we cannot create frontends for a subdomain (also we
don't have certificates for such domain).

Configure THEIA_WEBVIEW_EXTERNAL_ENDPOINT to something less secure, but
working in our environment. This fixes embedded jupyter notebooks and
other web views.

This is required, otherwise published URL in slapos master is `"None"`

After trying to generate a random image ourselve with image magic with:

    ${imagemagick:location}/bin/convert -size 6x6 xc: +noise Random \( -clone 0 -flip \) -append \( -clone 0 -flop \) +append -scale 128x128 $${:location}

I gave up and just download an image from gravatar, but ignoring errors
if any to comply with the "instanciation should work offline" rule.

like webrunner is doing

and stop creating some useless directories

To remove GIT_EXEC_PATH from environment as this can break running
buildout with slapos.recipe.build:gitclone sections using an
incompatible git version

So that we can access over IPv4 with a valid certificate

This required to generate a certificate, otherwise accessing from
frontend cause 404 site not served on this interface

We don't want theia to use /tmp/ this prevents running more than one
instance (for example we can only install vscode extensions once. golang
language server is also broken)

I set that to try to be independent from user config files/environment
variables, but that was a bad idea and not needed (I did that to
investigate an issue I had with jedi, but it was not depending on
environment variables - it was depending on the presence of a
buildout.cfg in current directory)

Cloud & Desktop IDE https://www.theia-ide.org/

This version is inspired from "theia-full-docker" from
https://github.com/theia-ide/theia-apps so it includes all extensions.
Many language servers are missing in this version (basically only go,
typescript and python language servers are installed).
PHP extension is not even installed.