Add narrow() like haystack's (adds filter query (fq))

add fq parameter and set up as a SearchNode like `where`
add narrow() to query object
add narrow_group() to allow grouping of narrows with either 'and' or 'or' in a
 parenthesized set
Add parameter to allow for inclusing of non-model fields

fields that come back from search but aren't defined in the model can now be
included on the return object. The object is cloned to a ModelLookalikeObject
which stops any automatic execution of @property fields whose name collide with
search data