export list symbols

[Zhanna Tsitkova]

Hello!
As part of the crypto modularity effort I have done  a simple analysis of libk5crypto.export list and suggest to remove some of the symbols  from this list. It may be done without hurting the kerb libs (link) integrity reducing the number of the symbols from ~160  to ~70. The attached libk5crypto.export_extras contains the list of the candidates for the removal. The updated libk5crypto.exports is also attached. 
Also, I suggest to rename the following APIs by prefixing them krb5int_ instead of krb5_ as these functions do not belong to the public API group. 
krb5_c_weak_enctype
krb5_encrypt_data
krb5_hmac
krb5_arcfour_decrypt krb5_arcfour_encrypt krb5_arcfour_encrypt_length
krb5_cksumtypes_length krb5_cksumtypes_list
krb5_decrypt_data krb5_derive_key krb5_derive_random
krb5_dk_decrypt krb5_dk_encrypt krb5_dk_encrypt_length krb5_dk_make_checksum 
krb5_enctypes_length krb5_enctypes_list
krb5_MD4Final krb5_MD4Init krb5_MD4Update
krb5_MD5Final krb5_MD5Init krb5_MD5Update
krb5_nfold
krb5_old_decrypt krb5_old_encrypt krb5_old_encrypt_length
krb5_random_confounder
krb5_raw_decrypt krb5_raw_encrypt

Thanks,
Zhanna