Split cci_thread_init into per-process and per-thread portions

Split cci_thread_init into per-process and per-thread portions

Call the per-thread code on thread attach and per-process once per
process.  Previously, while the function was named 'thread', it was
only actually called once per process.  Currently, the per-thread
code does nothing on non-windows platforms and is not even actually
invoked.

Fixes a windows bug when multiple non-main threads try to use ccapi
at the same time.

Signed-off-by: Kevin Wasserman <kevin.wasserman@painless-security.com>
ticket: 7050

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@25569 dc483132-0cff-0310-8789-dd5450dbe970