tpl: Allow 'Querify' to take lone slice/interface argument
Querify can now take a lone string/interface slice (with string
keys) as a parameter, or multiple string parameters, to build
URL queries.
Querify earlier used 'Dictionary' to add key/value pairs to a
map to build URL queries. Changed to dynamically generate ordered
key/value pairs. Cannot take string slice as key (earlier
possible due to Dictionary).