Handles better the memory utilization

- Added reference counts to Rule and AuditLog;
- Some memory leaks were removed, including GeoLookup;
- Deal better with parser errors;
- Overriding the AutlogLogWritter destructor.

src/audit_log_writer_parallel.h

@@ -31,7 +31,7 @@ class AuditLogWriterParallel : public AuditLogWriter {
     explicit AuditLogWriterParallel(AuditLog *audit)
         : AuditLogWriter(audit) { }
 
-    ~AuditLogWriterParallel();
+    ~AuditLogWriterParallel() override;
     bool init() override;
     bool write(Assay *assay, int parts) override;