Change some dependency rules to make them work with MMS/MMK (VMS make utilities).

The VMS make utilities always need an action if they determine that a target is
older than a denpendency element.

Besides, rules like

some/header.h : some/source.c

some/source.c : some/file.dump
	$(PMC2CC) some/source.pmc

don't reflect the building process, as both the C and header file are generated
by the $(PMCCC) call.
added a simple sort benchmark
added command line option
updated docs
Merge remote-tracking branch 'mrshu/simple_sort_benchmark' into mrshu/simple_sort_benchmark-gh917
Run tools/dev/mk_manifest_and_skip.pl so that sort.pir gets added to the manifest
added a simple sort benchmark
added command line option
updated docs
Run tools/dev/mk_manifest_and_skip.pl so that sort.pir gets added to the manifest
added default number of integers to sort
[codingstd] Add missing ChangeLog lines, fix socket.pmc line lengths
[GH #921] Fix tabs in src/dynpmc/Rules.mak cygwin/hpux

These missing tabs caused to miss the addgenerated lines for dynpmc libs.
[GH #921] cygwin Fix Could not create //usr/local/share/parrot/4.11.0-devel/MANIFEST

catdir with "" creates //.
[GH #922] addgenerated dynpmc headers in make, not pmc2c

rakudo and nqp do not have to clean a generated MANIFEST.generated.
[GH #893] add test for threaded say, mixup with \n

Test that for each say a \n is printed per thread.
Test it on a multi-core machine with

    watch prove -v t/op/say.t
[GH #893] improve concurrent say. concat with \n, then puts

Provide better atomicity with threads. To avoid mixing strings with
newlines in most cases. This is not foolproof of course.
concat only if it will not extend the already allocated buffer to
avoid copying.
make bootstrap-ops for say
[GH #893] Refactor better atomic say op: test for 80% success, concat if the buflen < 80

Since even SREGs are constant, Parrot_str_concat will always create a copy. So allow small cheap copies.
Merge branch 'rurban/threaded-say-gh893'
[codingstd] cuddled else in t/op/say.t