man: Add examples for userservices

Reverted previous three changesets (e09139525580, 85517c8fde36, 3acbff727626)

Modify userinfo output to indicate when domain defaults are displayed When Account instances reference NULL tid/qid/ssid, the data must come from the associated domain, and this should be indicated. For transport and services, this is easy to do as the string passed in the info dict can simply be modified. For quotalimit, however, another method must be used due to the CLI-side formatting. All approaches use a common formatter outsourced to the common.py file.

Modify Account class to handle NULL references This patch modifies the Account class to defer to using the associated domain's tid/ssid/qid fields if the per-instance fields are None/NULL.