[pcp] pcp updates

[Ken McDonell]

pmdaCacheStoreInst is now called pmdaCacheStoreKey and is joined by
pmdaCacheLookupKey.

Also some more fluffing about with pmlogrewrite.

Changes committed to git://oss.sgi.com/kenj/pcp.git dev

 man/man3/pmdacache.3        |  145 ++++++++++++++---
 src/GNUmakefile             |    2 
 src/include/pmda.h          |    9 -
 src/libpcp_pmda/src/cache.c |  364 +++++++++++++++++++++++++++++++++++++-------
 src/pmlogrewrite/indom.c    |   34 +++-
 src/pmlogrewrite/logio.c    |    2 
 src/pmlogrewrite/result.c   |   62 +++++++
 7 files changed, 535 insertions(+), 83 deletions(-)

commit 3671a98acb42c2200030fc2d028d83fc860cdc48
Author: Ken McDonell <kenj at internode.on.net>
Date:   Thu Sep 29 17:04:13 2011 +1000

    pmlogrewrite - checkpoint and backout
    
    This commits my latest changes (mostly indom metadata rewrite
    fixups), but also takes pmlogrewrite out of the build ... the code
    is not done yet, and there is no man page, so it is not ready
    for escape.

commit f1ac0f474eb0fec769a80c13ac18099400ccbf5d
Author: Ken McDonell <kenj at internode.on.net>
Date:   Thu Sep 29 16:46:30 2011 +1000

    libpcp_pmda - add (long) opaque key support
    
    Specifically pmdaCacheStoreKey() and pmdaCacheLookupKey() may be used to
    provide "hints" to be used when assigning an internal instance identifier.
    The "hints" are arbitrary sized binary data, so could much longer than
    the 2^31-1 limit for an instance identifier.
    
    Hashing ensures the hint -> instance identifier mapping is consistent
    across uses and platforms with minimal chance of collisions, so this
    provides a convenient way to map N-dimensional, 64-bit and other object
    identifier schemes to instance identifiers within an instance domain.