2-add-keyword-support (#6)

More development.

More types.
Fixed attribute groups in requests.
Started on client.
Saving data to file.

More types. Printing from chromeos works a little bit.

More types.

Spelling corrections.

WIP: Fix keyword handling

Move request to a separate file and add test.

Co-authored-by: Henrik Sölver <henrik.solver@gmail.com>
Reviewed-on: #6
Co-Authored-By: henrik <henrik.solver@gmail.com>
Co-Committed-By: henrik <henrik.solver@gmail.com>

packages/ipp/urivalue.go

@@ -9,7 +9,7 @@ type uriValue struct {
 	value string
 }
 
-func newUriValue(name, value string) *uriValue {
+func NewUriValue(name, value string) *uriValue {
 	u := new(uriValue)
 	u.name = name
 	u.value = value