[Scopes] Synchronize scopes and filters (fix issue60)

3 main changes in this PR:
 1. Move `processScopes` to `commonAdmin` directory
 1. Synchronize filters and scopes (fix issue #60 )
 1. Fix multi-group scopes management (especially for generated views)

Demo repository updated to test this behavior.

PR ready to merge, waiting for your feedbacks

/cc @loostro 
Please add a comment here `/* scopes must be processed before filters */` so in future, we don't forget that (it's not obvious by looking at the code).