Handle logfile paths that end in '|', treat it as a command to read data from.

Handle logfile paths that end in '|', treat it as a command to read data from.

* pcp/src/pmdas/logger/util.c: New file.
* pcp/src/pmdas/logger/util.h: Ditto.
* pcp/src/pmdas/logger/event.c (event_init): Handle opening pipe "paths".
  (event_shutdown): New function that stops piped processes and closes all
  files.
* pcp/src/pmdas/logger/event.h: Added event_shutdown() prototype.
* pcp/src/pmdas/logger/logger.c (read_config): Moved lstrip/rstrip code to
  util.c.
  (main): Calls event_shutdown() after pmdaMain() returns to clean
  everything up.
* pcp/src/pmdas/logger/GNUmakefile.in: Added util.c and util.h.
* pcp/src/pmdas/logger/Install: Support entering pipe "paths".