migrate fully to meson build system

- drop old build system
- move shared include and source files to common directory
- drop "rc-" prefix from shared include and source files
- move executable-specific code to individual directories under src
- adjust top-level .gitignore file for new build system

This closes #489.

support/Makefile

@@ -1,20 +0,0 @@
-# Copyright (c) 2017 the OpenRC Authors.
-# See the Authors file at the top-level directory of this distribution and
-# https://github.com/OpenRC/openrc/blob/HEAD/AUTHORS
-#
-# This file is part of OpenRC. It is subject to the license terms in
-# the LICENSE file found in the top-level directory of this
-# distribution and at https://github.com/OpenRC/openrc/blob/HEAD/LICENSE
-# This file may not be copied, modified, propagated, or distributed
-# except according to the terms contained in the LICENSE file.
-
-MK=		../mk
-include		${MK}/os.mk
-
-SUBDIR=		deptree2dot init.d.examples openvpn
-
-ifeq (${OS},Linux)
-SUBDIR+=	sysvinit
-endif
-
-include		${MK}/subdir.mk

support/deptree2dot/Makefile

@@ -1,9 +0,0 @@
-MK=	../../mk
-include ${MK}/os.mk
-
-DIR=	${DATADIR}/support/deptree2dot
-BIN=	deptree2dot
-INC=	README.md
-
-
-include ${MK}/scripts.mk

support/init.d.examples/.gitignore

@@ -1,11 +0,0 @@
-avahi-dnsconfd
-avahid
-dhcpcd
-dbus
-hald
-named
-ntpd
-openvpn
-polkitd
-sshd
-wpa_supplicant

support/init.d.examples/Makefile

@@ -1,11 +0,0 @@
-DIR=	${DATADIR}/support/init.d.examples
-INC=	README.md
-SRCS=	avahi-dnsconfd.in avahid.in dhcpcd.in dbus.in \
-	hald.in named.in ntpd.in \
-	openvpn.in polkitd.in sshd.in wpa_supplicant.in
-BIN=	${OBJS}
-
-MK=	../../mk
-
-include ${MK}/os.mk
-include ${MK}/scripts.mk

support/openvpn/Makefile

@@ -1,9 +0,0 @@
-MK=	../../mk
-include ${MK}/os.mk
-
-DIR=	${DATADIR}/support/openvpn
-BIN=	down.sh up.sh
-INC=	README.md
-
-
-include ${MK}/scripts.mk

support/sysvinit/Makefile

@@ -1,8 +0,0 @@
-MK=	../../mk
-include ${MK}/os.mk
-
-DIR=	${DATADIR}/support/sysvinit
-INC=	halt.sh inittab README.md
-
-
-include ${MK}/scripts.mk