Fix ccapi rpc methods to always pass 8 byte handles instead of sizeof(void*).

Fix ccapi rpc methods to always pass 8 byte handles instead of sizeof(void*).
ccapi server always stores all 8 bytes, whether compiled as 32 bit or 64 bit.
If 32 bit, client zero-pads handle when sending and truncates when receiving.

Signed-off-by: Kevin Wasserman <kevin.wasserman@painless-security.com>
git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@25265 dc483132-0cff-0310-8789-dd5450dbe970