Use object representation
Change docstring path style for multiple types

This changes the style we specify paths in the  docstring when we use
the same code to allow accessing an object by different datatypes (i.e.
boht by id and name), as propoed by opalmer.
Use to_schema twice and merge

Instead of hardcoding the schema, we now merge the dicts returned by
JobTypeVersion.to_schema() and JobType.to_schema().
Simplify getting max version in PUT

As suggested by opalmer
Empty lines to improve code readability

A few empty lines to partition the code into paragraphs sould improve
readability slightly.  The root problem is still the sheer size of this
if-block, though.
Check for version not None instead of just version

"if version" would return false if someone passes a 0
Style fix: comma on same line, not next