add a function for the version string and a "basic" VTC

src/tests/00basic.vtc

+# looks like -*- perl -*-
+
+varnishtest "vcl.use and .discard, and version string"
+
+server s1 {
+} -start
+
+varnish v1 -vcl+backend {
+	import blobcode from "${vmod_topbuild}/src/.libs/libvmod_blobcode.so";
+} -start
+
+varnish v1 -vcl+backend {
+} 
+
+varnish v1 -cli "vcl.list"
+varnish v1 -cli "vcl.use vcl1"
+
+varnish v1 -cli "vcl.use vcl2"
+varnish v1 -cli "vcl.use vcl1"
+
+varnish v1 -cli "vcl.show vcl1"
+varnish v1 -cli "vcl.use vcl2"
+varnish v1 -cli "vcl.discard vcl1"
+varnish v1 -cli "vcl.list"
+
+varnish v1 -vcl {
+	import blobcode from "${vmod_topbuild}/src/.libs/libvmod_blobcode.so";
+	backend b { .host = "${bad_ip}"; }
+
+	sub vcl_recv {
+	  return(synth(200));
+	}
+
+	sub vcl_synth {
+		set resp.http.x-version = blobcode.version();
+		if (!resp.http.x-version) {
+			set resp.status = 500;
+		}
+		return(deliver);
+	}
+}
+
+client c1 {
+	txreq -url "/"
+	rxresp
+	expect resp.status == 200
+	expect resp.http.x-version ~ "^.+$"
+} -run

src/vmod_blobcode.c

@@ -29,6 +29,8 @@
 #include <errno.h>
 #include <pthread.h>
 
+#include "config.h"
+
 #include "vcl.h"
 #include "vrt.h"
 
@@ -487,3 +489,9 @@ vmod_transcode(VRT_CTX, VCL_ENUM decs, VCL_ENUM encs, const char *p, ...) {
 	wb_advance(&wb, len);
 	return wb_finish(&wb, NULL);
 }
+
+VCL_STRING __match_proto__(td_blobcode_version)
+vmod_version(VRT_CTX __attribute__((unused)))
+{
+	return VERSION;
+}

src/vmod_blobcode.vcc

@@ -173,6 +173,14 @@ Example
 	``set req.http.Hex2Base64 = blobcode.transcode(decoding=HEX,``
                                     ``encoding=BASE64, encoded="666f6f");``
 
+$Function STRING version()
+
+Description
+	Returns the version string for this VMOD.
+
+Example
+	``std.log("Using VMOD blobcode version " + blobcode.version());``
+
 $Object blob(ENUM {IDENTITY, BASE64, BASE64URL, BASE64URLNOPAD, HEX} decoding,
              STRING_LIST encoded)