Added Enable/Disable All Buttons
Analog buffer sharing crash by memcpying for the AnanlogSignal::paint
Tolerate unexpected packets rather than asserting
Moved SamplingBar into pv::toolbars namespace
Renamed pv::view::LogicSignal::LogicSignalColours to SignalColours
Setup analog probe colours
Various tidyups in LogicSnapshot
Added a scale factor to AnalogSignal
WIP: Ananlog O(log N) painting