Introduce nvim namespace: Move files.

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.

src/nvim/indent_c.h

@@ -0,0 +1,12 @@
+#ifndef NEOVIM_INDENT_C_H
+#define NEOVIM_INDENT_C_H
+#include "vim.h"
+int cin_islabel(void);
+int cin_iscase(char_u *s, int strict);
+int cin_isscopedecl(char_u *s);
+int cin_is_cinword(char_u *line);
+int get_c_indent(void);
+void do_c_expr_indent(void);
+void parse_cino(buf_T *buf);
+pos_T * find_start_comment(int ind_maxcomment);
+#endif