trace_mpath: draw node names every 15cm, not every 300us
trace_mpath: draw node names every 15cm, not every 300us

-> improves view with other scale factors than 20us (the default)
jvf/scalaris,scalaris-team/scalaris,caijieming-baidu/scalaris,caijieming-baidu/scalaris,caijieming-baidu/scalaris,jvf/scalaris,jvf/scalaris,jvf/scalaris,caijieming-baidu/scalaris,caijieming-baidu/scalaris,scalaris-team/scalaris,jvf/scalaris,scalaris-team/scalaris,scalaris-team/scalaris,scalaris-team/scalaris,jvf/scalaris,caijieming-baidu/scalaris,scalaris-team/scalaris,scalaris-team/scalaris,scalaris-team/scalaris,caijieming-baidu/scalaris,jvf/scalaris