[imp] IMSP edits

[R Phillips]

It's possible we are one of the few still keeping an IMSP configuration
because we have offered it for a long time now.  However I've had to
make the same edits for a few versions and also for the new groupware
5.1 so I thought I would feedback in case anyone else has similar
experiences.

First off I don't know when the change from plaintext to Plaintext came
about, but that was fairly easy to work out what the following web log
error meant :

PHP Fatal error:  Class 'Horde_Imsp_Auth_plaintext' not found in
.../Horde/Core/Factory/ImspAuth.php on line 105

conf.local.php
$conf['imsp']['auth_method'] = 'Plaintext';

The next error meant I went to look back at previous versions and just
amended it back to what it was:

PHP Fatal error:  Using $this when not in object context in
.../Horde/Core/Factory/ImspAuth.php on line 95

From:
$class = $this->_getDriverName($driver, 'Horde_Imsp_Auth');

To:
$driver = basename($driver);
$class = 'Horde_Imsp_Auth_' . $driver;


The next one:
PHP Fatal error:  Class 'Horde_Imsp' not found in
.../Horde/Imsp/Auth/Plaintext.php on line 36

Meant changing from:
if (preg_match(Horde_Imsp::MUST_USE_LITERAL, $userId)) {

To:
if (preg_match(Horde_Imsp_Client_Base::MUST_USE_LITERAL, $userId)) {

on lines 36 and 43 of Plaintext.php

And the same edit for this error:
PHP Fatal error:  Class 'Horde_Imsp' not found in
.../Horde/Imsp/Client/Base.php on line 128

For some historical reason I can't really recall, probably when looking
at debugging I put in a firebreak in Horde/Imsp/Book.php around line
1031, but I don't think I've hit it in production.

if(!isset($parts[$i+2])) {
  $this->_imsp->_logger->err(sprint('IMSP Parsed beyond end looking for
double quote %s', print_r($parts, true)));
  throw new Horde_Imsp_Exception('Problem parsing IMSP address book');
}

Anyway, hope that helps someone, or more likely, I'm probably missing
something...