pcp updates - fix pcp-iostat QA issues and use SIGPIPE SIG_DFL

[Mark Goodwin <mgoodwin@xxxxxxxxxx>]

This fixes the QA issues reported by Ken on older python versions
(e.g. RHEL6 / python-2.66). Also: use SIG_DFL SIGPIPE handler to
avoid the unwanted socket.error exceptions on SIGPIPE.

pmiostat QA now passes on f23 with python2 and python3, and also on RHEL6
with python 2.66 (I could repro the issues Ken reported on RHEL6 but not on f23)


Changes committed to git://git.pcp.io/mgoodwin/pcp master

commit 2ad730b4a58e30a0ae14d5d8248d918d4688019d
Author: Mark Goodwin <mgoodwin@xxxxxxxxxx>
Date:   Thu Feb 11 15:49:02 2016 +1100

    pmiostat: use SIG_DFL to ignore SIGPIPE and avoid socket.error exceptions
    
    Python installs a sigpipe handler and throws a socket.error exception
    on broken pipe - override this with a SIGPIPE SIG_DFL handler to avoid
    the unwanted exceptions.

commit 83b7b4fff6580d924073968cb8a5b717d329eb16
Author: Mark Goodwin <mgoodwin@xxxxxxxxxx>
Date:   Thu Feb 11 14:56:03 2016 +1100

    pmiostat: correctly use a class instance of IostatOptions to check args
    
    Use an instance of IostatOptions to check args. This fixes a coding issue
    with older python versions (e.g. python 2.6.6 on RHEL6), and QA breakage.