- re-worked PNS_LINE_PLACER and PNS_ROUTER classes a bit, removing duplicate class members
- cleaned up Andrew's blind/buried via fixes
- fixed 'custom via width' dialog bug updating the width even when closed/cancelled
- fixed incorrect radius of drawn microvias
Added REASON enum for Reset() function, so tools will know why a reset occured.
Fixed SELECTION_TOOL (it was bailing out, when a new board was loaded and some items were still selected).
Added removal of VIEW_ITEM groups after changing layers and removing items.