Support If-[Un]Modified-Since for object HEAD

We already supported it for object GET requests, but not for
HEAD. This lets clients keep metadata up-to-date without having to
either fetch the whole object when it's changed or do their own date
parsing. They can just treat Last-Modified as opaque and update their
idea of metadata when they get a 200.

Change-Id: Iff25d8989a93d651fd2c327e1e58036e79e1bde1
Use eventlet instead of threading for timeout

The only explicit use of Python threading is found in the
testFileSizeLimit test. Using eventlet seems a bit easier to follow,
accomplishing the same goal, and does not constrain us to a
multi-threaded environment.

The chunks() and timeout() module level functions are only used by one
test each, so we just move them to those tests to indicate they are not
used globally.

Change-Id: I50b9fb798fbfd1d552b3c3f90309f6b86da34853
Fix logging issue when services stop on py26

On older versions of python 2.6, exceptions would be spewed to the error
log whenever a service would stop.  This gets magnified by the
container-updater which seems to do it with every pass.  This catches
and squelches the error.

Change-Id: I128c09c240e768e8195af1f6fe79b10d4e432471
Closes-Bug: #1306027
Add includes of referenced SAIO bin scripts

Change-Id: I6810e69a757336a3aed0a38146c27f270fe2dde1
Merge "Use eventlet instead of threading for timeout"
Merge "Fix logging issue when services stop on py26"
Merge "Add includes of referenced SAIO bin scripts"
Print 'Container Count' in data base info

Currently, 'Container Count' was missing in data base info.
So this patch will help printing 'Container Count' also.

Change-Id: I1ca80ee79e71b086b30fd2d1ab024ea1cfb324f5
Merge "Support If-[Un]Modified-Since for object HEAD"
Merge "Print 'Container Count' in data base info"
Fix testcase test_print_db_info_metadata()

Test compares cluster info to hardcoded expected data and wasn't
sorting the two sets of things being compared leading to some
sporadic unit test failures.

Change-Id: I3ef98260a62c15d06ba8cc196196d4e90abca3f0