Added PreferencesDialog, game/mod directories, reloading MetaEvents, etc.
Renamed stuff for consistency.
Added control points to node connections.

Left-click-drag on a connection line segment to add a new point.
Right-click while dragging to cancel.

Left-click-drag an existing control point to move it.
Left-click-release without moving to remove a control point.
Implemented reading/writing a connection's control-points.
Allow nodes to form connections with themselves.
Removed scripted.pro.user.