Bug 64188 - getVersionHistory does not follow total parameter

When a version history is already loaded, decreasing the total
parameter getVersionHistory() now returns the decreased amount
of values.

Fixed also for getVersionHistoryTable() and fullVersionHistory()
methods.

Created namedtuple classes:
- HistEntry
- FullHistEntry
to improve handling of data returned by getVersionHistory().

Adapted scripts to make use of new classes.

Fixed also a bug in page.previousRevision(), when page is  new page.

Bug: 64188
Change-Id: I9aa1372e7e6366e3dee454d069b742abbc372b64
Merge "Bug 64188 - getVersionHistory does not follow total parameter"