add missing <algorithm> header to util.hpp
fix indentation of macros in lobby_main.cfg
add GUI tag list for Vim syntax highlighting
delete deprecated NDEBUG flag from VC project
new GUI2 widget: num_box

This widget implements the integer_selector interface and can therefore
directly replace sliders.

In text.hpp, the private variable 'text_' had to be changed to protected
status to access it in num_box.
register num_box for compilation & syntax
changelog entries