src/tty/tty.h:
src/tty/tty-slang.c:
src/tty/tty-ncurses.c: new tty_fill_region() function.
src/dialog.c (widget_erase, dlg_erase): tty_fill_region() function
is applied to erase area of widget and dialog.
Created some TTY functions instead of MC core global variables.
Moved init_layer() function from MC core to TTY layer.
Renamed slang_init() to init_slang().
Added required #include's in TTY layer.
Moved S-Lang color and attribute definitions from src/tty/tty-slang.h
to colors-slang.h.