[asterisk-dev] [Code Review] Fix misuses of ast_str

[Walter Doekes]

>  struct ast_str *str = ast_str_create(32);
>
>  foo(str);
>
>  do_something(str); /* DANGEROUS */

Ouch. That's unexpected.

Could you do an update of the doxygen in include/asterisk/strings.h 
too?

/w