Refactor API types and prototypes

- Split functions with multiple files in the 'api' subdirectory
- Move/Add more types in the 'api/defs.h' header
- Add more prototypes
- Refactor scripts/msgpack-gen.lua
- Move msgpack modules to 'os' subdirectory

src/api/vim.c

@@ -0,0 +1,140 @@
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "api/vim.h"
+#include "api/defs.h"
+
+void vim_push_keys(String str)
+{
+  abort();
+}
+
+void vim_command(String str, Error *err)
+{
+  abort();
+}
+
+Object vim_eval(String str, Error *err)
+{
+  abort();
+}
+
+int64_t vim_strwidth(String str)
+{
+  abort();
+}
+
+StringArray vim_list_runtime_paths(void)
+{
+  abort();
+}
+
+void vim_change_directory(String dir)
+{
+  abort();
+}
+
+String vim_get_current_line(void)
+{
+  abort();
+}
+
+void vim_set_current_line(String line)
+{
+  abort();
+}
+
+Object vim_get_var(bool special, String name, Error *err)
+{
+  abort();
+}
+
+void vim_set_var(bool special, String name, Object value, Error *err)
+{
+  abort();
+}
+
+String vim_get_option(String name, Error *err)
+{
+  abort();
+}
+
+void vim_set_option(String name, String value, Error *err)
+{
+  abort();
+}
+
+void vim_del_option(String name, Error *err)
+{
+  abort();
+}
+
+void vim_out_write(String str)
+{
+  abort();
+}
+
+void vim_err_write(String str)
+{
+  abort();
+}
+
+int64_t vim_get_buffer_count(void)
+{
+  abort();
+}
+
+Buffer vim_get_buffer(int64_t num, Error *err)
+{
+  abort();
+}
+
+Buffer vim_get_current_buffer(void)
+{
+  abort();
+}
+
+void vim_set_current_buffer(Buffer buffer)
+{
+  abort();
+}
+
+int64_t vim_get_window_count(void)
+{
+  abort();
+}
+
+Window vim_get_window(int64_t num, Error *err)
+{
+  abort();
+}
+
+Window vim_get_current_window(void)
+{
+  abort();
+}
+
+void vim_set_current_window(Window window)
+{
+  abort();
+}
+
+int64_t vim_get_tabpage_count(void)
+{
+  abort();
+}
+
+Tabpage vim_get_tabpage(int64_t num, Error *err)
+{
+  abort();
+}
+
+Tabpage vim_get_current_tabpage(void)
+{
+  abort();
+}
+
+void vim_set_current_tabpage(Tabpage tabpage)
+{
+  abort();
+}