Remove plugins from Shout

[jecisc]

In Shout we have a variable plugins but this is never used. This is dead code that we could remove.

Since we are in freeze phase I'm opening an issue instead of doing the change to remind me to do it when P13 branch will open

[MarcusDenker]

check with @estebanlm

[MarcusDenker]

The problem is that if we use a Plugin to change the syntax (like estabans exeriment with strings), we might want to do syntax highlight of that, too.

This is part of a bigger question: support experiments on the compiler (be it with plugins or by using a different compiler) has not enough support right now on the tooling side (syntax hightlight, code completion....).