Eliminate default member values from route query

Generating a route from a request DTO currently produces redundant
parameters for value types that are equal to their default value. This
change modifies RouteMember so that it only returns a non-null value to
be contributed to the route if the current value is not equal to that
type's default value.
Unit tests for elimination of default route values

Tests to verify previous commit.
Merge pull request #515 from pdegenhardt/master

Eliminate default member values from route query