When the random seed is purposely made predictable for testing purposes
by using the CURL_ENTROPY environment variable, process that data in an
endian agnostic way so the the initial random seed is the same
regardless of endianness.
- Change Curl_rand to write to a char array instead of int array.
- Add Curl_rand_hex to write random hex characters to a buffer.
Fixes#1315Closes#1468
Co-authored-by: Daniel Stenberg
Reported-by: Michael Kaufmann