pcp

PM_TYPE_EVENT support - round round two

• add pmUnpackEventRecords and pmFreeEventResults to libpcp and
  associated man pages

• add endian safe encode/decode for PM_TYPE_EVENT values sent via PDUs
  ... implies working through each event parameter of each event record
  packed into the value

• move __pmTimeval declaration from impl.h to pmapi.h ... it is needed
  for pmEventRecord (struct timeval won't work across platforms)

• tweak the sample PMDa with some more metrics for event parameter types
  to cover all the PMAPI value types

• add -x option to pminfo (like -f, but expand event records if they
  are found)