This function can be called by modules to allow FS-specific
modules to gather data for a given file path/file descriptor.
Currently integrated into POSIX and STDIO modules.

- remaining items are tracked in gitlab issues

- untested

Conflicts:
	darshan-log-format.h
	darshan-runtime/Makefile.in
	darshan-util/Makefile.in
	darshan-util/darshan-logutils.h

There are cases where lustre stripe info is not available the
first time a given file is opened (e.g., when using the
llapi_file_create call). So, now we call into the lustre module
every time a file is opened to give the module a chance to gather
data.

Conflicts:
	darshan-bgq-log-format.h
	darshan-runtime/darshan.h
	darshan-runtime/lib/darshan-bgq.c
	darshan-runtime/lib/darshan-core.c
	darshan-runtime/lib/darshan-posix.c
	darshan-util/darshan-convert.c
	darshan-util/darshan-diff.c

some bugs were causing the regression tests to fail when using
LD_PRELOAD instrumentation method

- eliminated 110 SLOC
- untested

- note: darshan-stdio module updates are still needed; this merge just
  updates the rest of the code and resolves conflicts

fixed bugs that prevented record names from mapping to file systems in darshan-util; also fixed thread safety and deadlock issues

Merging mmap feature development branch back into master. Darshan
can now mmap its data structures to temporary log files at runtime to
protect against applications that do not call MPI_Finalize. Feature
can be enabled at configure time using '--enable-mmap-logs'.