Unchecked return values in ipa-join
    
    krb5_get_default_realm() and asprintf() return values were ignored.
    This could lead to unhandled error issues or memory access
    issues.
    
    This patch adds return value checks to all such functions.
    As a consequence, one new return value has been added to man page.
    
    https://fedorahosted.org/freeipa/ticket/720