Implement new when_all (working on #1278: Implement improved when_all/wait_all)
(cherry picked from commit 44e9a3acfa0a581582e6bd85212069f0f447073e)

Conflicts:
	hpx/lcos/when_all.hpp
Fixing return value of when_all_n. This requires some additional thought, though.
(cherry picked from commit 6fbf067f83d5a4520995f8faa54c8278fc14ae3d)
Adjust docs and return type for when_all_n algning things with latest changes on master
(cherry picked from commit 486370b35464c13e3bf4f5ae296c567343480309)
Re-implementing wait_all using techniques similar to dataflow() and the new when_all. This fixes #1278: Implement improved when_all/wait_all
(cherry picked from commit 12968b85f812dec56538285dba279049114d68ad)
Getting rid of an allocation in wait_all.
(cherry picked from commit 61480372c5d134df9a1d379772f5656b2979ee96)
Adding closed tickets to docs
(cherry picked from commit 85bb61be2cdf6b30595b73493a6b0ea6cc9232d3)
Minor error message fix for Xeon/Phi
(cherry picked from commit c3033298209c4a7f75db11928dfe42b56a6d4f18)
Honor HPX_MAX_COU_COUNT during build if specified
(cherry picked from commit ed7f8f5ee035c78e0ad021fd53659e6830a85795)
Adding log output for hwloc topology information
(cherry picked from commit ac9f3c5c3fcae6e05440f5f38cde546c9054a311)
shared_future::then is const
(cherry picked from commit 8ad0620ff976111d6d91576750701e2c7a489906)
Trying to address linker error using Intel in iostreams module (see comments in #1280)
(cherry picked from commit ce4be2e6564e270d9d9489d1650e58e3069c6caa)
Removing static string constant definitions
(cherry picked from commit d6e86aabc6e1c8b89e163a9cacb243e9ab72edcf)