Add stand-alone example program w/ Makefile and README

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

example/README.md

@@ -0,0 +1,55 @@
+Stand-alone Example syslogp() Application
+=========================================
+
+This is a *very* simple stand-alone example application.  The purpose is
+to show how to use the sysklogd 2.x API, e.g. `syslogp()`, to use "new"
+RFC5424 features like MsgID.
+
+Included in this directory are two files:
+
+ - `example.c`: actual C code example
+ - `example.mk`: plain Makefile for building `example`
+
+Provided the two files are in the same (writable) directory, you can
+build the application like this:
+
+    make -f example.mk
+
+
+GNU Autotools
+-------------
+
+If you want to use GNU autoconf & automake instead.  The following is
+recommended in `configure.ac` and `Makefile.am` to build your
+application.
+
+```sh
+# configure.ac (snippet)
+
+# Check for pkg-config tool, required for next step
+PKG_PROG_PKG_CONFIG
+
+# Check for required libraries
+PKG_CHECK_MODULES([syslog], [libsyslog >= 2.0])
+```
+
+and
+
+```Makefile
+# Makefile.am (snippet)
+
+bin_PROGRAMS    = example
+
+example_SOURCES = example.c
+example_CFLAGS  = $(syslog_CFLAGS)
+example_LDADD   = $(syslog_LIBS)
+```
+
+**NOTE:** Most free/open source software that uses `configure` default
+  to install to `/usr/local`.  However, some Linux distributions do no
+  longer search that path for installed software, e.g. Fedora and Alpine
+  Linux.  To help your configure script find its dependencies you have
+  to give the `pkg-config` a prefix path:
+
+    PKG_CONFIG_LIBDIR=/usr/local/lib/pkgconfig ./configure
+