This is to make it possible, in the future, to create multiple instances
of `NotCurses` for multiple terminals. The first instance of
`NotCurses` becomes the default one, so that any instances of other
classes that aren't explicitly created with a pointer to another
`NotCurses` instance still work as expected.
Note that currently trying to call `notcurses_init` twice results in the
following error for me:
0x55555559bfc0 is already registered for signals
Couldn't drop signals: 0x55555559bfc0 != 0x5555555b6720
terminate called after throwing an instance of 'ncpp::init_error*'
Program received signal SIGABRT, Aborted.
The error is signalled by `setup_signals` and the pointer shown in the
message points to the first `struct notcurses` instance created.
* CMake: add USE_PANDOC, USE_DOXYGEN options #101
* README: mention rust
* start integrating rust into build #101
* CMake: add USE_NETWORK option for cargo
* Debian: build-dep on doxygen
* rust: colloquy checks in Cargo.lock
* extract NCKEY defines into their own include
* colloquy: use clap to parse CLI args
* CMake: unify option namespace
* Python: update include path
* Rust: fix up --frozen workings for -DUSE_NETWORK=off
* CMake: abstract out colloquy a little
* Sync direct.hh to the New Way
