Added very simple logger, to track execution flow.
Added first, simple logging (debug messages) to main, DataManager, DynDBDriver and ReportManager.
DynDBDriver::DRCursor can obtain DRs occurring after given one (by id).

ReportManager uses this feature to prepare Cursor for new data, when no more data in DB is available yet.
Added invokeLater (by Qt's emit), to ensure execution of View's rendering from proper thread (GUI thread).