s/pic_proc_cv_reserve/pic_proc_cv_init/g
pic_symbol_p macro is replaced with pic_sym_p
make gensym API public
leave a comment about conv parameter of pic_new_var is nullable
C APIs to modify global varaibles
wrapper/unwrapper for var-proc conversion
functions defined by pic_defun will be implicitly renamed
add defvar
add missing 'static' modifier