Add support for auto-detetcing OS heading for progress

This patch removes the cognitive overhead of having to manually set your
OS heading, --with-heading="Foo OS vX.YY".  As of this patch, Finit by
default extracts PRETTY_NAME from /etc/os-release.  It is now possible
to also disable the heading entirely using --without-heading

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

contrib/alpine/build.sh

@@ -18,7 +18,7 @@ PKG_CONFIG_LIBDIR=/usr/lib/pkgconfig:/usr/local/lib/pkgconfig ./configure	\
 		 --sysconfdir=/etc		--localstatedir=/var		\
 		 --enable-dbus-plugin		--enable-x11-common-plugin	\
 		 --enable-alsa-utils-plugin	--with-watchdog			\
-		 --with-heading="Alpine Linux"  --with-keventd
+		 --with-keventd
 
 echo
 echo "*** Building ..."

contrib/debian/build.sh

@@ -26,8 +26,7 @@ echo
     --sysconfdir=/etc                 --localstatedir=/var		\
     --enable-dbus-plugin              --enable-x11-common-plugin	\
     --enable-alsa-utils-plugin	      --with-keventd			\
-    --with-random-seed=/var/lib/urandom/random-seed			\
-    --with-heading="Debian GNU/Linux"
+    --with-random-seed=/var/lib/urandom/random-seed
 
 if [ $? -ne 0 ]; then
     echo

contrib/void/build.sh

@@ -18,7 +18,7 @@ PKG_CONFIG_LIBDIR=/usr/lib/pkgconfig:/usr/local/lib/pkgconfig ./configure	\
 		 --sysconfdir=/etc              --localstatedir=/var		\
                  --enable-dbus-plugin           --enable-x11-common-plugin	\
 		 --enable-alsa-utils-plugin	--with-watchdog			\
-		 --with-heading="Void Linux"    --with-keventd
+		 --with-keventd
 
 echo
 echo "*** Building ..."