1) Add highlighting to simProbe and simTune tools.
2) Probe tool should accept wires and pins, not wires and components.
3) Give simulator window a flat look to match rest of Kicad.
4) Collapse whitespace out of simulator window.
5) Add some error messages.
6) Add some whitespace to simulation setting dialog.
Replace all instances of "component" and "part" with "symbol" when
referring to schematic and library symbols.
Replace all instances of "component" with "footprint" when referring to
board and library footprints.
Minor dialog layout fixes to some of the dialogs impacted by the UI
string changes.
