not if they aren't in 5.4, too.

This reverts the following commits:

974324676b2436f159f42d9241c569f813471684
4662151ea7d7b6920d115cf2a2d6e9d4232727a3
84fe2cc890e49f40bac7c3ba74b3cfc6dc4cef2f

This does not revert the JSON changes released in PHP 5.3.14.

Use salt_len_in instead of strlen(salt) or PHP_MAX_SALT_LEN, otherwise too
much memory will be allocated.

sha512 has a 86 character checksum, not 43. That probably was a copy&paste
from the sha256 code which indeed has 43.

The allocation also was using sizeof(char *), thus allocating 4 or 8 times
as much memory as necessary. The sizeof(char *) was removed in the 5.4
branch in b7a92c9 but forgotten on 5.3.

The memset 0 call was using PHP_MAX_SALT_LEN which can be smaller than the
output buffer and thus not zeroing out everything. Use the size of the
output buffer (needed) instead.