Changed default connection delay to be nonzero, and made negative values illegal.  Fixes long-standing problem with the Model Editor that when adding feedback projections, the network eventually goes into an endless loop, due to never-ending streams of event generation
Changed default connection delay to be nonzero, and made negative values illegal.  Fixes long-standing problem with the Model Editor that when adding feedback projections, the network eventually goes into an endless loop, due to never-ending streams of event generation

Tasignotas/topographica_mirror,mjabri/topographica,Tasignotas/topographica_mirror,mjabri/topographica,mjabri/topographica,ioam/topographica,ioam/topographica,mjabri/topographica,Tasignotas/topographica_mirror,ioam/topographica,mjabri/topographica,ioam/topographica,Tasignotas/topographica_mirror,Tasignotas/topographica_mirror,ioam/topographica