that now happens with multiple relation dialog with title.

otherwise full text index is used where keywords that appear in more than 50% of rows are ignored.

so that it supports other comparison operators like '>', 'like' etc.

Amend 9240d498: Since many Loaders are
instanciated by unittest itself, filter_test_list still have to be a class
variable

This reverts commit 15aaafbf.
Reason: To be consistent with packing list and order until
the new way of handling payment conditions is implemented.