Added support for out_to_ncurses

Added support for out_to_ncurses

All ERR()'s are renamed to NORM_ERR() and box to mbox so that they don't
clash with things in ncurses.h .
Ncurses is enabled by default when building conky but can be disabled with
--disable-ncurses .
At the moment configure doesn't check if ncurses is actually available.
I'm adding support for ncurses so that we can make as much things as possible
that are only available in X11 also available in console in the future.