Rather than inspecting CMAKE_BUILD_TYPE manually and setting
DEBUG_OPTIONS based off the results, set CMAKE_{C/CXX}_FLAGS_DEBUG,
and allow that to be picked up by CMake #565. Remove repeated -W
flags that were all over the place, making them global compiler
flags. Remove repeated FORTIFY=2 definition that was all over the
place, making it a global compiler definition. Remove all uses of
${DEBUG_FLAGS}. Also, since CMake doesn't define a CMAKE_BUILD_TYPE
by default, instead just setting neither debugging nor optimization
flags, in what seems a pretty fucking boneheaded move, set it by
default to RelWithDebInfo. ugh. Explicitly disuse unused PoC variables.
Added:
* class FDPlane (`ncfdplane*`)
* class Subproc (`ncsubproc*`)
* NotCurses: get_inputready_fd (`notcurses_inputready_fd`)
* Plane: qrcode (`ncplane_qrcode`)
* class PlotBase: templated base class for Plot variations
* class PlotU: `uint64_t` instantiation of PlotBase (aliased to previous
`Plot` class for source compatibility), `ncuplot*`
* class PlotD: `double` instantiation of PlotBase, `ncdplot*`
* fedora: dep on OpenImageIO, and use it
* fedora: dep on libqrcodegen-devel
* fedora: BuildRequires OpenEXR-devel
* tight check on USE_MULTIMEDIA
* CMake: enable notcurses-view for ffmpeg OR oiio
* notcurses-view: don't reach into libav
* oiio: ncvisual_render() #453
* oiio: need our own properly-offset ncvisual_plane()
* `visual` poc: accept optional command line argument
* oiio: work for 3-channel images #453
* oiio: destroy ncvisual's plane if we own it #453
* notcurses_visual.3: s/FFmpeg/multimedia/g
* jungle demo should be available outside of DFSG builds
* libav: blitters don't need FFMpeg
* CMake: threads independent of ffmpeg
* CMake: add USE_TESTS option to disable tests #450
* tetris: work without ffmpeg
* fedora: flesh out specfile #328
* menu poc: don't use ffmpeg at all
* compile PoCs with binary/include
* multiselect PoC: work without ffmpeg