(bug 66951) Fix getversion_nightly and check for IOError

- unnotified IOError caused that bug and general exceptions hides
  the right reason of it.
- the version file's information sequence might be change,
  reorder retrieving it.
- online parsing may be omitted
- synchronize some parts with core

Change-Id: Iec2a89f12b0c571c63b1b7c76d206b9b47d33f4f
Merge "(bug 66951) Fix getversion_nightly and check for IOError"