add per-instance array for tracking file status

instance array is for now max cluster members big.. could make it dynamic
4 helper functions for populating it, looking it up vi pid, getting and setting via fileInfo.fh
reworked separate function that separates starting and ending filenames
use pkg-config to determine compile flags
add call to separateEndingFile in access callback
protect NULL returns from strdup

if strdup cannot malloc memory, it returns NULL.  two instance fields could have
this happen.  before we dereference either, we need to verify it's not NULL.
add syslog init and log_info on start/stop
add opendir and releasedir to support flag_nopath if >= v2.9
use pthread_mutex to protect instances array pop/clear
return EROFS when opening file with O_CREAT or O_WRONLY
WIP: more work on separating clustered execution flow
version bump, define that is also in makefile removed
update readme to reflect design refinements
WIP: still more work on clustered execution flow

now waits for all cluster members to connect (delays and EINTR errors)
still outputs all of the specified file, does not advance to newer files