Instead of exposing native C types to a public API that can be consumed by other
platforms, we are now using the following translation:
int64_t -> Integer
double -> Float
bool -> Boolean
This should make the API simpler, and int64_t is enough to represent any integer
value we might need.
Range checks should be done inside the API functions, that way we can modify the
types of the actual fields/variables modified by the API without changes to the
API prototypes.
Problem: Some newly introduced files used includes relative to the
current file, both of the form `include "../XXX.h"` and
`include "XXX.h"`.
Preferred form is relative to include root (src/ in our case).
Solution: Change includes to preferred form.
Note: This is also done to ease next commit (prepend 'nvim/ to all
project-local includes).
Move files from src/ to src/nvim/.
- src/nvim/ becomes the new root dir for nvim executable sources.
- src/libnvim/ is planned to become root dir of the neovim library.
