Add a comment documenting where libssl depends upon the current (objectionable)
behaviour of this code, to prevent people from blindly changing it.
BUF_MEM_grow_clean() takes a size_t as the size argument. Remove false comments
mentioning it's an int, bogus (int) casts and bounds checks against INT_MAX
(BUF_MEM_grow_clean has its own integer bounds checks).

ok deraadt@
Change the actual default for returned asn1 strings to be utf8 in the code,
rather than only in the config file, to trip people up later.
Found, and fix pleaded for by <spider@skuggor.se> who apparently
spent hours chasing it down.
ok miod@