Provide access to RequestContext  #669

Current Situation

Currently, only Django-IDOM has access to the current websocket's scope. However, this is very commonly needed within all web frameworks to provide access to things such as user attributes, login, and logout functionality.

See #594

Proposed Actions

Create a RequestContext to be used with the upcoming use_context hook.

Work Items

• Create RequestContext on a per web-framework basis
• Document this feature (Probably also want an example on user login/logout)