NIM Kerberos 5 Provider corrections

NIM Kerberos 5 Provider corrections

	When validating a Kerberos 5 principal name, the request
	to the KDC should not request forwardable, renewable, or
	proxiable options as these may be blocked by policy and
	will result in the return of an error.

	Always treat the Kerberos 5 principal name as valid
	unless the KDC returns an error that clearly indicates that
	the principal name does not exist.

	Use a MEMORY: ccache for temporary storage instead of an
	API: ccache.

	Initialize pointer values with NULL instead of 0.

ticket: new
tags: pullup
component: windows

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@19069 dc483132-0cff-0310-8789-dd5450dbe970