FIX joins unicity

On rails-3, joins statements from different queries would not be made
properly unique, which caused sql errors.

Turned out [uniq queries method was
bogus](https://github.com/oelmekki/activerecord_any_of/blob/ee7f010382772ffa7c232f2a489cfcbcb639cbd4/lib/activerecord_any_of/alternative_builder.rb#L46)
and did not actually reduce queries array, it only worked on rails-4
because active_record was checking for duplicate itself later.
Merge pull request #23 from oelmekki/fix_join_unicity

FIX joins unicity
FIX using all or none

When passing a query with `Model.all` or `Model.none`, we get a
`NoMethodError: undefined method 'or' for nil:NilClass` due to not
constraints being set by arel.
Fixed by modifying original query to use `where('0=1')` or
`where('1=1)`.

Rel #22