refs #478, use data cache in readers

* URLs no longer have to be passed
* watchdog for DB readers to check DB status

In same step:
* fixed some log messages and comments
* allow to self signed SSL certificates
* adjusted namespace for CNetworkUtils (now in network)

src/blackmisc/threadedreader.cpp

@@ -9,6 +9,9 @@
 
 #include "threadedreader.h"
 
+using namespace BlackMisc;
+using namespace BlackMisc::Network;
+
 namespace BlackMisc
 {
     CThreadedReader::CThreadedReader(QObject *owner, const QString &name) :