Add Facelets attribute to limit EL scope to explicitly declared parameters

>>>>> On Mon, 09 Aug 2010 21:08:00 -0400, Ryan de Laplante said:

R> It would be nice have a new attribute on ui:composition and ui:decorate
R> that tells it to NOT allow the template have access to the global EL
R> context. Instead, only the ui:insert and ui:param values within the
R> ui:composition or ui:decorate would be accessible to the template.
R> This I would enable me to allow my customers to input their own facelet
R> templates from the web UI of the SaaS application.
#### Environment
Operating System: All
Platform: Sun
#### Affected Versions
[1.1]

Start by locating the Facelets handling for ui:composition and ui:decorate, then review how their ui:insert and ui:param values interact with the EL context. Check existing template and EL tests if available; done means an attribute can restrict templates to explicitly declared parameters without access to the global context.

Written by the indexing model from the issue text.