Address Darshan-parser  seg fault issue and print OST obdidx in one line

See merge request !11

* mpi-io-test case now also checks that the DXT parser can handle
  a log file with no DXT data
* a new mpi-io-test was added to run with DXT tracing enabled
  to ensure DXT and it's parser are both functioning properly

Signed-off-by: CongXu <cong.xu@intel.com>

disable mmap wrapper for dynamic linking

Closes #223

See merge request !10

see #223

Issue 219 dxt mem config

See merge request !9

this allows us to request memory allocations at smaller granularity
than MiB