Use $(localstatedir)/run instead of $(runstatedir)

`runstatedir` is only available in Autoconf 2.70, but unless the
distribution is a bleeding edge system, it most likely uses Autoconf
2.69. That said, several major distributions have backported runstatedir
support to the older versions, hiding the issue. See #35.

This change replaces all references to runstatedir to use
$localstatedir/run instead, which is what is recommended by the autoconf
manual.

This also updates the build instructions to add --localstatedir and
--sysconfdir. This is because the lack of the options would have them
default to `$(prefix)/var` and `$(prefix)/etc` respectively, and with
prefix set to `/usr`, these would be the bogus directories `/usr/var`
and `/usr/etc`.

INSTALL.md

@@ -46,10 +46,13 @@ You will also need the `cmocka` package to run the unit tests.
 2. Run autogen.sh
 3. Run the following commands:
 ```
-./configure --prefix=/usr
+./configure --prefix=/usr --localstatedir=/var --sysconfdir=/etc
 make && sudo make install
 ```
 
+You may want to remove or edit the `--prefix=/usr` option, most users prefer
+non-distro binaries in `/usr/local` (default without `--prefix`) or `/opt`.
+
 ## Configuration options
 
 ### udev

daemon/Makefile.am

@@ -26,7 +26,7 @@ x52d_CFLAGS = \
 	-DSYSCONFDIR=\"$(sysconfdir)\" \
 	-DLOCALEDIR=\"$(localedir)\" \
 	-DLOGDIR=\"$(localstatedir)/log\" \
-	-DRUNDIR=\"$(runstatedir)\" \
+	-DRUNDIR=\"$(localstatedir)/run\" \
 	@PTHREAD_CFLAGS@ $(WARN_CFLAGS)
 
 x52d_LDFLAGS = @PTHREAD_LIBS@ $(WARN_LDFLAGS)
@@ -51,7 +51,7 @@ x52dconf_DATA = daemon/x52d.conf
 
 install-exec-hook:
 	$(MKDIR_P) $(DESTDIR)$(localstatedir)/log
-	$(MKDIR_P) $(DESTDIR)$(runstatedir)
+	$(MKDIR_P) $(DESTDIR)$(localstatedir)/run
 
 EXTRA_DIST += \
 	daemon/daemon.dox \