new container flags

[Attention: This patch increments EDITLEVEL in patchlevel.h, rendering all
 previous save and bones files obsolete.]

Here's the first cut at the two recommended flags lknown and cknown.
I've attempted to stay close to Pat's recommendations:
   "Containers ought to have two new flags:  lknown for lock status known,
    and cknown for contents known (ie, `secret').  Formatted box and chest
    descriptions should include locked/unlocked/broken when that is known
    and empty/nonempty (or something like "holds N items") when contents
    are known. The contents indicator would also apply to nonlockable
    containers."

I probably overlooked a place where a flag should be adjusted, but this
should give us a good starting point.

I wasn't sure what to do with the case of the auditory feedback for
magical locking "Click" and "Clunk". The question that came to my mind
was: Should those reveal the locked or unlocked status of a box?
I suppose if you knew the type of wand you were zapping or the spell
you were casting, you could argue that they should.

In the end, I opted for setting lknown right off the zap/cast effect
for anyone playing a Wizard role, and not setting it for anyone else,
thus advancing class differentiation a little bit too.

I haven't checked the cknown results under all flags.menu_style options
at this point, only MENU_FULL.

doc/fixes35.0

@@ -115,6 +115,8 @@ vampires can now shapeshift into bats and fog clouds; the latter can be done at
 	will to slip through locked doors
 shapeshifted vampire will transform back to vampire form after you defeat it and
 	continue to fight in its native form
+container lknown flag for locked/unlocked/broken awareness
+container cknown flag for container content awareness
 
 
 Platform- and/or Interface-Specific New Features