Plugin update

Hi,

Ok, this need some testing.

What this do now:
- Run a .sh at install (if the plugin require it)
- Run s .sh at uninstall (if the plugin require it)
- redirect after install (if the plugin require it)
- list plugins
- Install plugins
- Download and install
- Remove
- plugin settings
- add to menu

What is work in progress:

- setting api
- pool api

Tell me if there is something that you don't like.