hygiene, put bound checks into zif_trans() and zif_type()

Signed-off-by: Sebastian Freundt <hroptatyr@fresse.org>
minor, eradicate hinted THIS parameter from transition/offset finders

Signed-off-by: Sebastian Freundt <hroptatyr@fresse.org>
minor, print previous transition in reverse order (the previous transition comes first, then the current one)

Signed-off-by: Sebastian Freundt <hroptatyr@fresse.org>
fix, PEBKAC, in a zrng's .next slot there will be INT_MAX at most

Signed-off-by: Sebastian Freundt <hroptatyr@fresse.org>
test, put some regressions in for Asia/Singapore and --prev/--next zone inspection

Signed-off-by: Sebastian Freundt <hroptatyr@fresse.org>
Merge branch 'cmd/dzone'

* cmd/dzone:
  test, put some regressions in for Asia/Singapore and --prev/--next zone inspection
  fix, PEBKAC, in a zrng's .next slot there will be INT_MAX at most
  minor, print previous transition in reverse order (the previous transition comes first, then the current one)
  minor, eradicate hinted THIS parameter from transition/offset finders
  hygiene, put bound checks into zif_trans() and zif_type()