Context Integration

Attached patch adds a Context Reaction plugin for Environment Indicator. In any given Context, you can declare that the EI module should be activated, and configure it, using the site-wide configuration as defaults.

It will only show itself if the site-wide configuration is disabled, and only the first context (somewhat arbitrary) to declare an Environment Indicator reaction will actually control what happens.

In a short time I will also be bringing a Content Condition plugin to the Environment module. This combination will enable environment indicators in the sidebar to be linked to different environment/deployment states, and all will be packagable in a Feature.