pcp updates: improve collectl2pcp for disk.dm metrics and associated qa updates

[Mark Goodwin <mgoodwin@xxxxxxxxxx>]

Changes committed to git://git.performancecopilot.org/markgw/pcp/pcp.git master

commit d7477092b25e29ac6022d116d03ca0fe4cd6e19f
Author: Mark Goodwin <mgoodwin@xxxxxxxxxx>
Date:   Tue Apr 14 15:34:11 2015 +1000

    Support pmiostat -x dm for archives converted by collectl2pcp.

    Collectl doesn't collect persistent dm-* mapped names, so just
    export the dm-* name from /proc/diskstats as the instances for
    disk.dm metrics rather than lump them all together as disk.dev.
    PCP archives created by collectl2pcp now work with pmiostat -x dm

        modified:   src/collectl2pcp/disk.c
        modified:   src/collectl2pcp/metrics.c
        modified:   src/collectl2pcp/pmdesc.c

commit a89b9591e55a96bf5ab4d29c5e04063a43b4e1d6
Author: Mark Goodwin <mgoodwin@xxxxxxxxxx>
Date:   Wed Apr 15 14:21:13 2015 +1000

    remake since checksum changed after collectl2pcp changes.

        modified:   qa/544.out

commit f672b43b9e18b105ece4f90528b89ff93d90ac8a
Author: Mark Goodwin <mgoodwin@xxxxxxxxxx>
Date:   Wed Apr 15 14:18:23 2015 +1000

    split pmiostat tests for sd and dm metrics on collectl2pcp archive.

        modified:   qa/536
        modified:   qa/536.out