New syntax for the substituted variables - $(var).

Improved the variable substitution (all references in a string are replaced).
Added special redirect loading code (to separate card dependant code to
single files).

src/cards/SI_7018.conf

@@ -0,0 +1,18 @@
+#
+# Configuration for the SI7018 chip
+#
+
+pcm.surround40_0_trident_dx_nx {
+	$.0 CARD
+	$.1 DEV
+	$.CARD {
+		type integer
+	}
+	$.DEV {
+		type integer
+	}
+	type hw
+	card $(CARD)
+	device $(DEV)
+	subdevice -1
+}