Enhanced query support for alert DB API and bug fixes
Enhanced query support for alert DB API and bug fixes

mrkeng/alerta,skob/alerta,skob/alerta,0312birdzhang/alerta,mrkeng/alerta,mrkeng/alerta,0312birdzhang/alerta,skob/alerta,mrkeng/alerta,guardian/alerta,guardian/alerta,0312birdzhang/alerta,guardian/alerta,skob/alerta,guardian/alerta