V104 QUICK FINITE-FAULT EDITOR COMPILE FIX

Base
- Starts from V103.

Fix
- Adds forward declarations for quick finite-fault editor functions that are used before their definitions:
  * open_quick_finite_fault_editor(HWND owner)
  * quick_ff_draw_preview(HDC hdc)

Why
- V103 called quick_ff_draw_preview() from draw_scene_to_hdc() before the function body.
- V103 also called open_quick_finite_fault_editor() from quick_ff_wnd_proc() before the function body.
- In C this caused implicit declarations, then conflicting static declarations later.
