Bug fixes for Wings3d pre 1.5 (Snapshot 2)

NOTE
- Unhide all objects in UV editor window was not working. Reported by Misty Wisty; [Micheus]
- User hotkeys have precedence over default values added to the list in the initialization time. On this case, default entries are removed. Reported by haroon [Micheus]
-  Unhide adjacent faces were crashing when object has other than default material applied to it; [Micheus]
- Fixed an issue related to dynamic dialogs and  preview dialog feature on wings_ask.erl; [Micheus]