v0.2.9

• Add: PointerEvent carries ctrlKey/metaKey/shiftKey/altKey (the live modifier
  state, incl. on move) on all 3 engines + FakeAdapter — lets consumers gate drag
  behaviour on a held modifier (e.g. Ctrl/⌘ to translate rigidly instead of deform). All
  optional + default false (non-breaking); FakeAdapter.send(...) takes an optional
  mods arg. Treat ctrlKey || metaKey as "the modifier" (Ctrl on PC/Linux, ⌘ on Mac).