Split out interface specific parts of abc.c
abc: Remove use of sockfd_global in interface part
Fix abc.c includes
Merge branch 'master' into NetworkManager

Conflicts:
	src/Makefile.am
	src/abc.c
Const'ify: char * interface
First version of abc-networkmanager
Add check for OpenSSL
Show configure summary
declare variable on definition
Configure: Check for and add --disable-network-manager flag
abc: conditionally include abc-networkmanager.h
Implement get_conn_obj and abc_nm_enable_wireless
Make copy of dbus reply strings, as dbus eventually overwrites them.
configure: Rework NM autodetection
abc: rework interface so that it supports multiple backends

Supported interfaces are link-time dependent,
chosen interface is run-time specific.
That is, one backend per abc invocation
abc: cleanly split out wifi backends (iw/networkmanager)
abc: add NetworkManager wifi configuration backend
abc: add iw wifi configuration backend

This is mostly the original abc(-wifi) code
abc: conditional makefile
abc-iw: documentation update