Avoid repeatedly serializing and splitting the root path component of
jobs being added to the list to be processed and returned.
Attempting to split a string path using 'job' introduces a bug if a job
ever happens to also use the name 'job' as part of its name. This could
be fixed by using root.split('/job/') but it still seems hackish.
Maintain the root path to the folder in the hierarchy as a list of path
components, add to it when descending and store the result of joining
it with '/job/' as a separate variable to avoid needing to re-parse.
Change-Id: I074ad74ad935c50716141a79822ca84999734c3f
49d6c92d0c