Revert "Revert "use POSIX version of esrerror_r""
Revert "Revert "use POSIX version of esrerror_r""

This reverts commit ecd6ba76783c7f3cf2bd4bacce760bc37c17007f.

Conflicts:
	os/FStream.cpp

Because it introduced problems on OSX
Use strerror only, simplify

scottpurdy/nupic.core,jaredweiss/nupic.core,pettitda/nupic.core,metaml/nupic.core,numenta/htmresearch-core,ywcui1990/nupic.core,utensil/nupic.core,pettitda/nupic.core,brev/nupic.core,rhyolight/nupic.core,rhyolight/nupic.core,numenta/nupic.core,utensil/nupic.core,jaredweiss/nupic.core,numenta/nupic.core,pettitda/nupic.core,EricSB/nupic.core,lscheinkman/nupic.core,akhilaananthram/nupic.core,jaredweiss/nupic.core,Bemujo/https-github.com-numenta-nupic,Bemujo/https-github.com-numenta-nupic,scottpurdy/nupic.core,rcrowder/nupic.core,EricSB/nupic.core,neuroidss/nupic.core,sambitgaan/nupic.core,lscheinkman/nupic.core,rhyolight/nupic.core,numenta/htmresearch-core,subutai/nupic.core,lscheinkman/nupic.core,utensil/nupic.core,lscheinkman/nupic.core,neuroidss/nupic.core,ywcui1990/nupic.core,ywcui1990/nupic.core,utensil/nupic.core,numenta/nupic.core,numenta/htmresearch-core,metaml/nupic.core,subutai/nupic.core,brev/nupic.core,numenta/nupic.core,EricSB/nupic.core,akhilaananthram/nupic.core,jaredweiss/nupic.core,EricSB/nupic.core,pettitda/nupic.core,metaml/nupic.core,scottpurdy/nupic.core,rcrowder/nupic.core,brev/nupic.core,rcrowder/nupic.core,akhilaananthram/nupic.core,subutai/nupic.core,Bemujo/https-github.com-numenta-nupic,sambitgaan/nupic.core,sambitgaan/nupic.core,rhyolight/nupic.core,neuroidss/nupic.core,rcrowder/nupic.core,numenta/htmresearch-core,breznak/nupic.core,brev/nupic.core,Bemujo/https-github.com-numenta-nupic,metaml/nupic.core,ywcui1990/nupic.core,breznak/nupic.core,subutai/nupic.core,neuroidss/nupic.core,akhilaananthram/nupic.core,scottpurdy/nupic.core,breznak/nupic.core,sambitgaan/nupic.core,breznak/nupic.core