cosmetics, use standard terminology
minor, provide interval x instant predicates
minor, provide interval x interval predicates
minor, provide bitte_scan() to query for facts in a valid time slice
test, provide regression for bitte_scan()
minor, use _bitte_trend() to obtain transactions in scan mode
hygiene, rename _bitte_rtr_trend() -> _bitte_trend() as it's used in scan mode too
minor, provide bitte_hist() to retrieve the history of one fact
test, provide regression for bitte_hist()
Merge branch 'core/bitte'

* core/bitte:
  test, provide regression for bitte_hist()
  minor, provide bitte_hist() to retrieve the history of one fact
  hygiene, rename _bitte_rtr_trend() -> _bitte_trend() as it's used in scan mode too
  minor, use _bitte_trend() to obtain transactions in scan mode
  test, provide regression for bitte_scan()
  minor, provide bitte_scan() to query for facts in a valid time slice
  minor, provide interval x interval predicates
  minor, provide interval x instant predicates
  cosmetics, use standard terminology