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