add .vimrc and src/.ycm_extra_conf.py
Include <stdint.h> in types.h
Replace UINT32_T by uint32_t
Remove useless sizeof(uint32_t) == 4 test
Extract indent_c.c from misc1.c
Adapt include guards to the style guide
Use include paths relative to src/

As described in Google's style guide, the basis for Neovim's

> All of a project's header files should be listed as descendants of the
> project's source directory without use of UNIX directory shortcuts .
> (the current directory) or .. (the parent directory).

Add src as an include directory to facilitate this.
Add basic unit test + pendings for mch_[gs]etperm.
Use preprocessor trick to import 'defines'.
Add tests for non existing file.
Move mch_[gs]etperm to os/fs module.
Refactor os/fs module.
Ignore test/includes/post/.
Move vim_fname from misc1 to os/fs.
Rename vim_fexists to file_exists.
Remove misuse of mch_getperm.
Add unit tests for file_exists.
Fix invocation of file_exists.
Replace chmod with uv_fs_chmod call.
Rename file_exists to os_file_exists.