video: Refresh Windows display list on WM_DISPLAYCHANGE

- Displays may have been added, removed or changed and all cached monitor
  handles are invalidated as a result.

- Display events are handled in three steps:
  1. Mark all currently know displays as invalid
  2. Enumerate all displays, adding new ones and marking known displays as valid
  3. Remove all displays still invalid after enumeration

- Display connect/disconnect events are sent when displays are added or removed
  after initial setup
3 files changed