parser: refactor network to use rule class as its base.

There is one significant difference in the encoding of the network
rules. Before this change, when the parser was encoding a "network,"
rule, it would generate an entry for every family and every
type/protocol. After this patch the parser should generate an entry
for every family, but the type/protocol is changed to .. in the pcre
syntax. There should be no difference in behavior.

Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>

parser/parser_policy.c

@@ -33,6 +33,7 @@
 #include "parser.h"
 #include "profile.h"
 #include "parser_yacc.h"
+#include "network.h"
 
 /* #define DEBUG */
 #ifdef DEBUG