accept_sec_context.c (krb5_gss_accept_sec_context): Eliminate double

accept_sec_context.c (krb5_gss_accept_sec_context): Eliminate double
	free of ap_req.data, and initialize ctypes to be NULL to avoid freeing
	a pointer to stack garbage when doing a V1 mechanism
	accept_sec_contxt.

init_sec_context.c: Re-arrange program logic to simplify and factor
	out code; fix gss_init_sec_context() so that if the default OID is
	passed to the init_sec_context, it will use the V1 mechanism if a
	single DES enctype is used.  Error handling was revamped to make it
	simpler and cleaner, and to assure that we don't have memory leaks on
	error returns.

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@11093 dc483132-0cff-0310-8789-dd5450dbe970