BUILD/MEDIUM: contrib: Dummy DeviceAtlas API.

Creating a "mocked" version mainly for testing purposes.
diff --git a/contrib/deviceatlas/dac.c b/contrib/deviceatlas/dac.c
new file mode 100644
index 0000000..7da6971
--- /dev/null
+++ b/contrib/deviceatlas/dac.c
@@ -0,0 +1,221 @@
+#include "dac.h"
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+static char const rcsid[] = "$Id: dac.c, v dummy 1970/01/01 00:00:01 dcarlier Exp $";
+
+struct da_bitset {
+    unsigned long bits[8];
+    size_t bit_count;
+};
+
+/*
+ * Constructor/Destructor for possible globals.
+ */
+
+void
+da_init()
+{
+}
+
+void
+da_fini()
+{
+}
+
+
+void
+da_seterrorfunc(da_errorfunc_t callback)
+{
+}
+
+const char *
+da_typename(da_type_t fieldtype)
+{
+   return "none";
+}
+
+char *
+da_getdataversion(da_atlas_t *atlas)
+{
+    return "dummy library version 1.0";
+}
+
+time_t
+da_getdatacreation(da_atlas_t *atlas)
+{
+    return time(NULL);
+}
+
+int
+da_getdatarevision(da_atlas_t *atlas)
+{
+    return 1;
+}
+
+da_status_t
+da_atlas_compile(void *ctx, da_read_fn readfn, da_setpos_fn rewind, void **ptr, size_t *size)
+{
+    return DA_OK;
+}
+
+da_status_t
+da_atlas_open(da_atlas_t *atlas, da_property_decl_t *extraprops, const void *ptr, size_t len)
+{
+    ptr = malloc(len);
+    return ptr ? DA_OK : DA_NOMEM;
+}
+
+void
+da_atlas_close(da_atlas_t *atlas)
+{
+}
+
+da_evidence_id_t
+da_atlas_clientprop_evidence_id(const da_atlas_t *atlas)
+{
+    return (da_evidence_id_t)2;
+}
+
+da_evidence_id_t
+da_atlas_accept_language_evidence_id(const da_atlas_t *atlas)
+{
+    return (da_evidence_id_t)3;
+}
+
+da_evidence_id_t
+da_atlas_header_evidence_id(const da_atlas_t *atlas, const char *evidence_name)
+{
+    return (da_evidence_id_t)1;
+}
+
+da_status_t
+da_atlas_getproptype(const da_atlas_t *atlas, da_propid_t propid, da_type_t *type)
+{
+    *type = DA_TYPE_BOOLEAN;
+    return DA_OK;
+}
+
+da_status_t
+da_atlas_getpropname(const da_atlas_t *atlas, da_propid_t propid, const char **name)
+{
+    *name = "isRobot";
+    return DA_OK;
+}
+
+da_status_t
+da_atlas_getpropid(const da_atlas_t *atlas, const char *propname, da_propid_t *property)
+{
+    *property = (da_propid_t)1;
+    return DA_OK;
+}
+
+size_t
+da_atlas_getpropcount(const da_atlas_t *atlas)
+{
+    return 1;
+}
+
+void
+da_atlas_setconfig(da_atlas_t *atlas, da_config_t *config)
+{
+}
+
+da_status_t
+da_searchv(const da_atlas_t *atlas, da_deviceinfo_t *result, da_evidence_t *evidence, size_t count)
+{
+    memset(result, 0, sizeof(*result));
+    result->propcount = count;
+    return DA_OK;
+}
+
+da_status_t
+da_search(const da_atlas_t *atlas, da_deviceinfo_t *result, ...)
+{
+    da_evidence_t vec[4]; /* XXX: this will have to grow if more evidence is supported. */
+    size_t i;
+    va_list args;
+    va_start(args, result);
+    for (i = 0; i < sizeof vec / sizeof vec[0];) {
+        vec[i].key = va_arg(args, da_evidence_id_t);
+        if (vec[i].key == 0)
+            break;
+        vec[i++].value = va_arg(args, char *);
+    }
+    va_end(args);
+    return da_searchv(atlas, result, vec, i);
+}
+
+/*
+ * Search-result centric functions.
+ */
+size_t
+da_getpropcount(const da_deviceinfo_t *info)
+{
+    return info->propcount;
+}
+
+da_status_t
+da_getfirstprop(const da_deviceinfo_t *info, da_propid_t **propid)
+{
+    if (info->propcount == 0)
+        return DA_NOMORE;
+    *propid = &info->proplist[0];
+    return DA_OK;
+}
+
+da_status_t
+da_getnextprop(const da_deviceinfo_t *info, da_propid_t **propid)
+{
+    if (*propid - info->proplist >= info->propcount - 1)
+        return DA_NOMORE;
+    ++*propid;
+    return DA_OK;
+}
+
+void
+da_close(da_deviceinfo_t *sr)
+{
+}
+
+da_status_t
+da_getpropname(const da_deviceinfo_t *info, da_propid_t propid, const char **name)
+{
+    *name = "isRobot";
+    return DA_OK;
+}
+
+da_status_t
+da_getproptype(const da_deviceinfo_t *info, da_propid_t propid, da_type_t *type)
+{
+    *type = DA_TYPE_BOOLEAN;
+    return DA_OK;
+}
+
+da_status_t
+da_getpropinteger(const da_deviceinfo_t *info, da_propid_t property, long *vp)
+{
+     *vp = -1;
+    return DA_OK;
+}
+
+da_status_t
+da_getpropstring(const da_deviceinfo_t *info, da_propid_t property, const char **vp)
+{
+    *vp = NULL;
+    return DA_OK;
+}
+
+da_status_t
+da_getpropboolean(const da_deviceinfo_t *info, da_propid_t property, bool *vp)
+{
+    *vp = true;
+    return DA_OK;
+}
+
+const char *
+da_get_property_name(const da_atlas_t *atlas, da_propid_t property)
+{
+    return "isRobot";
+}