For semantic consistency with the Rust API guidelines.
- rename most `NcChannel` & `NcCell` methods starting with `with_`* to `from_`*.
- update examples.
In order to be consistent with the rest of the naming scheme, and in order to avoid conflicts with the higher level rust wrappers, which will be using `Notcurses` for the wrapper struct from now on.
- also deprecate `NotcursesOptions` and rename it to `NcOptions`.
- update examples, docs and readme.
- remove `Nc` & `NcD` wrappers, to move them to notcurses-rs library.
- update the summary header format for Notcurses and NcDirect
- update docs and examples