Allow passing subroutine/function instead of i or tag.

If callable is passed, it will be called (without arguments) and
the value will be used instead.

lib/htlogr.pm

     my $tag     = shift;
     my $i       = shift;
 
+    $tag = &{$tag}()    if ref($tag) eq 'CODE';
+    $i = &{$i}()        if ref($i) eq 'CODE';
+
     my $uri;
     $uri .= $self->{path};
     $uri .= "?msg=" . uri_escape($msg);

lib/htlogr.py

         return self.DIV_FIELD.join(fields)
 
     def log(self, msg, tag=None, i=None):
-        params = {"msg": msg, "tag": tag, "i": i}
+        params = {"msg": msg}
+
+        try:
+            params["tag"] = tag()
+        except TypeError:
+            params["tag"] = tag
+        try:
+            params["i"] = i()
+        except TypeError:
+            params["i"] = i
+
         pq = "%s?%s" % (self.parsed_url.path, self._zipup_params(params))
         self.conn.request("GET", pq)
         self.last_error = None