bug#5570: automatic cache validation

[Paul Pogonyshev]

Alan Mackenzie wrote:
> Paul, would you please update your copy of the Emacs HEAD from savannah,
> and see if any indentation bugs still manifest themselves.  Thanks!

Yes they do.  I still see all kinds of indentation bugs, none seem to
be gone:

* Sometimes everything is topmost-intro; this may or may not be gone
  after buffer reload with C-x RET r, suggesting at least two sources
  for the bug.

* Indentation sometimes spuriosly changes when hitting TAB (e.g. TAB
  -> to 0th column, TAB again -> to 8th column, TAB third time -> to
  0th once more; no intervening keystrokes).

* Sometimes character after opening " gets eaten see #5851.

I did 'bzr pull', then 'make maintainer-clean && ./configure && make'
and then 'sudo make install'.

Paul