Updated unibilium to the latest stable release 2.0.0 as a requirement for Neovim 0.4.3.
Changelog:
- add support for the ncurses 6.1 "wide integer" 32-bit file format
- improve README.md with build instructions and prerequisites
- numeric capabilities are stored as ints now (used to be shorts)
- rewrite unibi_var_t internals (now the only official access is via the helper functions)
- try ncursesw6-config, ncurses6-config, ncursesw5-config, and ncurses5-config to get the list of terminfo directories (TERMINFO_DIRS) when building