Port EditWorld to wxWidgets

[muggenhor]

Edit World needs to be ported from ​MFC as ​GUI library to ​wxWidgets instead.

The following files need to be ported from using MFC to wxWidgets instead:

• brushprop.cpp
• btedit.cpp
• bteditdoc.cpp
• bteditview.cpp
• expandlimitsdlg.cpp
• mainfrm.cpp
• mapprefs.cpp
• objectproperties.cpp
• pasteprefs.cpp
• playermap.cpp
• tdview.cpp
• textureprefs.cpp
• textureview.cpp
• wfview.cpp

The following dialogs need to be ported from using MFC to wxWidgets instead:

• IDD_EDGEBRUSH (brushprop.cpp)
• IDD_EXPANSIONLIMITS (expandlimitsdlg.cpp)
• IDD_MAPPREFS (mapprefs.cpp)
• IDD_OBJECTPROPERTIES (objectproperties.cpp)
• IDD_PASTEPREFS (pasteprefs.cpp)
• IDD_TEXTUREPREFS (textureprefs.cpp)

[muggenhor]

(In [3450]) Don't depend on Windows API specific functions when an alternative is provided by the C library:

• Replace usage of WinAPI function lstrcmpA with libc function strcmp

This addresses #4

[Per]

Given the large map format changes that have happened and are planned for trunk, should we move this task into the dustbin?