* Some things go to the FILE* we're provided. Some can only go to a controlling terminal. Check to see if the FILE we're given is a TTY. If not, open up /dev/tty #752.
* term_emit(): fflush() can return EAGAIN. Loop on it to eliminate a rare error on shutdown that particularly affected unit tests (where we start and shut down Notcurses many times in a row).
* sgr poc: check return value of setlocale()
* drone: run all unit tests
* CMake: add some tests using PoCs
* ncneofetch: print even small palettes