Fix early bailouts on missing inbound filterValues. Update Lookup Strategy

1. Create a list of terms from the filterValue string
2. If only 1 term, set filterValue to that term.
3. If more than 1 term, find the length predominate term.
4. If filterValue.length is < 3, set the filterLimit to 10
5. Remove the length predominate term from the list of validation terms
6. Make a mozContact.find request with the length predominate term
    as the filter.filterValue.
7. In the mozContacts.find request success handler, filter the
    results by evaluating each contact record against
    the list of validation terms.

Signed-off-by: Rick Waldron <waldron.rick@gmail.com>