Use oslo network utils function to set tcp_keepalive

Use oslo network utils function to set tcp_keepalive

Earlier, tcp_keepidle was set to 600s and other parameters left to default
values. A new function was added to oslo-incubator for setting tcp keepalive
settings, and cinder should use this to set any values we want.
In addition to the existing cfg option for tcp_keepidle, new values were added
for tcp_keepalive(to turn on/off this feature, tcp_keepintvl(to specify gap
between successive probes) and tcp_keepcnt(to specify number of probes). To
mimic existing behavior, tcp_keepalive defaults to True, and tcp_keepidle to
600(seconds). The other two default to None, and the oslo code will ignore
them.
Ran update.py in oslo-incubator to copy changed modules into cinder.
Changes are:
network_utils.py (which contains the function we need, others are deps)
edd73c9 Merge "Improve help strings"
fe3389e Improve help strings
8a0f567 Remove str() from LOG.* and exceptions
f61a4e7 Fix python26 compatibility for RFCSysLogHandler
da6d713 Revert setting oslo-incubator logs to INFO
0d18381 Set default log levels for oslo.messaging and oslo-incubator

gettextutils.py
9912e5d Add API for creating translation functions
6cc96d0 Fix test_gettextutils on Python 3

jsonutils.py
9e5a393 jsonutils.load() accepts file pointer, not string
a6b2aec On Python <= 2.6, use simplejson if available
e3a1d9c Use six.moves.xmlrpc_client instead of xmlrpclib
3a31bba Python3 support for xmlrpclib
e6494c2 Use six.iteritems to make dict work on Python2/3

log.py
edd73c9 Merge "Improve help strings"
fe3389e Improve help strings
8a0f567 Remove str() from LOG.* and exceptions
f61a4e7 Fix python26 compatibility for RFCSysLogHandler
da6d713 Revert setting oslo-incubator logs to INFO
0d18381 Set default log levels for oslo.messaging and oslo-incubator

Current HEAD in OSLO:
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Merge: 2640847 e433899
Date:   Mon May 5 19:41:28 2014 +0000
Merge "Enable configuring tcp keepalive"
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Ran generate_sample to generate cinder.conf.sample

Implements blueprint configure-tcp-keepalive
Change-Id: I2e4c2327803c25e54ed771f25ef973bb543b9355