This abstraction did more harm than good -- pretended to create correct
JSON responses from a simpler structure, but created responses that were
very far from what Jenkins would return:
* "url" fields didn't contain folders, but nobody noticed as these
weren't used anyway
* "jobs" fields contained the string "null" (not JSON null, an actual
JSON string!), whereas real Jenkins returns a list of almost empty
objects (just a "class" field, if Jenkins is new enough, otherwise
nothing)
* "color" field is absent from folders
The usage of deepcopy, insert and append totally obstructed the real
contents of those responses from most readers. Let's just be a bit
verbose here, please.
Change-Id: Ida2cfa3662e491e4178228096dc622cdd859202f