- Rewrite of netconf get/get-config code

- Unified get and get-config code to single function get_common
  - Integrated list-pagination code
  - Moved get code to new files backend_get.[ch]

test/test_augment_state.sh

@@ -189,6 +189,7 @@ cat <<EOF > $fstate
 </global-state>
 EOF
 
+# Note Expect gbds(default) + gbos(optional), the latter given by file above
 EXPSTATE=$(cat <<EOF
 <global-state xmlns="urn:example:lib"><gbds>gbds</gbds><gbos>gbos</gbos><aug:gads xmlns:aug="urn:example:augment">gads</aug:gads><aug:gaos xmlns:aug="urn:example:augment">gaos</aug:gaos></global-state>
 EOF