o gptl.c
  - Detect if imperfect nesting occurred. If so, still stop the timer but
    do not meddle with the stackidx. Also, print an error message.
  - Obsolete "outdir".
  - If one or more calls to GPTLerror() occurred, say so in GPTLpr() and
    GPTLpr_summary(). Also: make GPTLnum_errors() a user-callable function.
  - Bugfix to avoid adding a child more than once, e.g. due to multiple calls
    to GPTLpr().
o Bugfix to gptlf.F90.template to include gptlprocess_namelist, and add the
  entry for gptlnum_errors().
o utils.c
  - Add code for counting calls to GPTLnum_errors().
  - Reduce max print from 500 to 10 (code may have many MPI tasks running)
  - Make all error prints start with GPTL...
o Added test suite entry outoforder.c to test imperfect nesting.
o NOTE: Minor but detectable impact on overhead
o getoverhead.c
  - Better overhead estimate
  - NOTE: Impact of imperfect nesting test on overhead was minor but detectable
o Cleaned up Makefiles in ctests and ftests