pull up r19864 from trunk

pull up r19864 from trunk

 r19864@cathode-dark-space:  jaltman | 2007-08-24 10:45:37 -0400
 ticket: new
 subject: NIM: Add Identity Provider Pre-Process Message
 component: windows

 The Network Identity Manager application does not provide a user
 interface for identity specification.  That responsibility lies with
 the identity provider.  Whenever a dialog needs to allow the user to
 specify an identity, the identity provider has to populate the dialog
 with the necessary controls so that the user can specify an identity.
 In the case of the Kerberos v5 identity provider, the controls allow
 the user to specify a username and a realm.

 Once the dialog is populated, the application will dispatch window
 messages to the identity provider.  The identity provider will handle
 the window messages and notify the application when the selected
 identity changes.

 One deficiency of the API was that there was no message to notify the
 identity provider that an identity selection has to be made
 immediately.  When the user invokes the default action for a dialog by
 hitting enter, the only message received by the dialog is a command
 identifier of the default action.  In this case, the identity provider
 will not get a chance to notify the application of the identity
 selection.

 This patch fixes the API deficiency by introducing a new message,
 WMNC_IDENT_PREPROCESS, which the application can use to notify the
 identity provider that the dialog box is about to be processed.  In
 response, the identity provider can notify the application of the
 selected identity even if no other messages were received by the
 identity provider.

ticket: 5685
version_fixed: 1.6.3

git-svn-id: svn://anonsvn.mit.edu/krb5/branches/krb5-1-6@19999 dc483132-0cff-0310-8789-dd5450dbe970