Updates specfile to match distro guidelines. Suppots modifying client directory path at build time.

- Support relocating client files at build time (required for LSB compliant nodes)
- OS varable added to perform some make choices
- Saving and exporting the Makefile vars now scripted using list of variables
- Updated specfile to match RH and SUSE requirements and guidelines
- Moved /usr/local/var to /var/local; dynamic files shall not use /usr.
- State files use %sharedstatedir for path (std for SLE and RHEL)
- Release value adjusted to meet different DEB and RPM reqs.

Signed-off-by: jcsiadal <jeremy.c.siadal@intel.com>

overlays/wwinit/etc/systemd/system/wwclient.service

@@ -1,14 +0,0 @@
-[Unit]
-Description=Warewulf node runtime overlay update
-After=network.target
-After=local-fs.target
-
-[Service]
-Type=notify
-ExecStart=/warewulf/bin/wwclient
-ExecReload=/bin/kill -s SIGHUP "$MAINPID"
-PIDFile=/var/run/wwclient.pid
-TimeoutSec=60
- 
-[Install]
-WantedBy=multi-user.target