Merge remote-tracking branch 'upstream/master'
Merge branch 'master' of https://github.com/chapel-lang/chapel
Adding spec entry for HeapSort
Fixing a typo; Adding a note about the reverse argument
Adding note for specifying stdin file in execopts
Initial draft of sets README
Initial draft of lsq readme
Slurm was complaining because threadring was calling exit(0).  Cause that not
to happen, and note that these tests will have it happen if they are run with
Slurm.
Clean up some more regressions from #420 sync-var-by-ref
Merge pull request #473 from vasslitvinov/fix-some-regressions-from-#420

Clean up some more regressions from #420 sync-var-by-ref

Nightly testing under FIFO with futures turned out some regressions.
I cleaned up some, added .bad, retired two obvious .futures.
Mostly I added .readFE/.readFF().
The log file did not have any fallouts from the new error
for min/max on sync/single/atomics.

I did not clean up the missing-.readFE error in these tests:
  test/types/single/sungeun/writeRecordInOutProc.future
  test/types/sync/sungeun/writeRecordInOutProc.future
  test/types/sync/sungeun/writeRecordOutProc.chpl

because they raise the issue we did not tackle in #420
and which we should discuss first.
Like other third-party packages, build the static, but not dynamic gmp libs

GMP seems to be breaking on the cray-prgenv-* builds, and I think that
the attempt to build .so's is the reason.  We could selectively disable
.so's on Crays, but since we disable the .so's in every other third-party
package, why not here as well?

Thomas is going to test this branch to see whether it fixes the GMP
builds on cray-prgenv-*.
Quiet new string tests.

- Throw --dataParTasksPerLocale=1 for promotion.chpl.  Using one tasks
  leads to consistent results and still tests what was originally
  intended (promotion, not task creation).

- Clarify comment in promotion.chpl

- Add another leakable type to begin.prediff (string reference count).

- Flush writes before checking memory to make sure that I/O buffers
  are freed.
Merge pull request #474 from sungeunchoi/test

Quiet new string tests.

- Throw --dataParTasksPerLocale=1 for promotion.chpl.  Using one tasks
  leads to consistent results and still tests what was originally
  intended (promotion, not task creation).

- Clarify comment in promotion.chpl

- Add another leakable type to begin.prediff (string reference count).

- Flush writes before checking memory to make sure that I/O buffers
  are freed.
Additions I forgot in the last commit.
Merge pull request #475 from sungeunchoi/test

Additions I forgot in the last commit.

These should have been part of #474.  I blame my cold.
Merge pull request #472 from lydia-duncan/silenceThreadringSlurm

Fix threadring slurm complaint

Slurm was complaining because threadring was calling exit(0). Cause that not
to happen, and note that these tests will have it happen if they are run with
Slurm.
Revert "Fix threadring slurm complaint"
Merge pull request #477 from chapel-lang/revert-472-silenceThreadringSlurm

Revert "Fix threadring slurm complaint"
Minor edits

Changed reference of file.open() to just open(), because it has been several
years since file.open() was a valid call.  Also, added a missing word.  It looks
like the document is up to date otherwise.
Merge pull request #478 from lydia-duncan/docFreezeIO

Minor edits to README.io [not reviewed]

Changed reference of file.open() to just open(), because it has been several
years since file.open() was a valid call. Also, added a missing word. It looks
like the document is up to date otherwise.