Parallax mapping with slope information.
Overriding normal maps.

Fixed lua error when none of the worlds or servers selected are and connect,
delete or configure buttons used.

Texture names must now be escaped in formspec elements image[],
background[], image_button[], image_button_exit[].

Instead of special-case handling of texture loading (and unloading
which was missing) in guiFormSpecMenu.cpp, use the newly created
ISimpleTextureSource interface which is a minimal subset of
ITextureSource. There is an implementation of this interface
used by GUIEngine (MenuTextureSource).

Fix an off-by-one bug in unescape_string; it caused requests for a
texture called "\0".

Add engine.gettext() and remove gettext() calls in guiFormspecMenu.cpp

Add old style mod selection in worldconfig dialog

Add missing file headers