Devel code for Sockets provider

Updated Makefile
Merge branch 'master' of https://github.com/jithinjosepkl/libfabric into devel

Conflicts:
	include/rdma/fabric.h
	prov/sockets/src/sock.h
	prov/sockets/src/sock_av.c
	prov/sockets/src/sock_cntr.c
	prov/sockets/src/sock_cq.c
	prov/sockets/src/sock_dgram.c
	prov/sockets/src/sock_dom.c
	prov/sockets/src/sock_ep.c
	prov/sockets/src/sock_eq.c
	prov/sockets/src/sock_fabric.c
	prov/sockets/src/sock_rdm.c