fix plotting future/past temp blockings

Need to explicitely turn off the temp blockings layer first.
.check_recurring_temp_blockings now part of do-checks
gpsman data viewer: shorten some header labels

"Accuracy" and "Symbol" header labels are now abbreviated.
gpsman data viewer: default toplevel geometry

The toplevel is a little bit broader to minimize the need for
horizontal scrolling.
add duplicate check for culdesac-orig
data update