Module deacivation option

[instantflorian]

For testing purposes it might be helpful to deactivate a module without completely removing it. The behavour of a deactivated module should be as if it is not installed, e.g. view.php / include.php are not excecuted and module stylesheets / javascripts are not loaded.

[WebDesignWorx]

Dev notes:

1. add column active to table {TP}addons
2. expand query code in https://github.com/WBCE/WBCE_CMS/blob/development/wbce/framework/frontend.functions.php#L325 in order to exclude Page-Module from output array when module inactive
3. apply for AdminTools also so that the inactive ones are excluded from view in /admin/admin-tools in the backend, are not accessible at all and don't execute anything