Use pool_blit_direct() instead of ncplane_putwc_yx() in
redraw_plot(). This eliminates use of rtl_egc() and wcwidth()
on the EGCs used in plots, sidestepping Debian's -1 wcwidth
for sextants (in the same fashion blitting does) and slightly
speeding up plot drawing. At a plot rate of 10Hz, notcurses-demo
is now faster than it used to be at 1Hz, so that's nice.
* use ioctl(KDGETMODE) to detect Linux console
* diagnostic on KDGETMODE
* add logdebug()
* unit test for notcurses_drop_planes(), add ncplane_putnstr_aligned()
* linuxconsole PoC
* linuxconsole: dump unicode->font table
* linuxconsole: explode glyphs
* linuxconsole: show 7 glyphs per 'line'
* linuxconjammer: shim console font with half blocks
* signals: handler for SIGTERM
* man pages: update notcurses_init() for options
* add NCOPTION_NO_FONT_CHANGES #201
