Make permissions suitable for multi-stores

[Michael-Herzog]

Permission to role mapping requires storeId field thus new table and migration of old mapping necessary. Permission role list gets store configuration panel similar settings configuration.

[mgesing]

As it may be difficult to administrate permissions this way, we should also think about alternative solutions (without going so deep), e.g. specifying the customer roles assigned to the customer depending on the store.

[mgesing]

See also #1178