[ansel] User configurable image formats for Ansel

[Heath S. Hendrickson]

Here are some patches to Ansel to support user configurable image 
formats (currently JPEG and PNG, but others should be possible based on 
IM and/or GD support) for the generated thumbnails and screen images.

I only had to patch ansel/lib/Ansel.php and ansel/config/prefs.php as 
Horde's image libraries already supported sending in a parameter array 
which could include a 'type' entry.

h

[root at space lib]# cvs diff Ansel.php
Index: Ansel.php
===================================================================
RCS file: /usr/local/horde/cvs/ansel/lib/Ansel.php,v
retrieving revision 1.30
diff -r1.30 Ansel.php
135c135
<         global $conf;
---
 >         global $conf, $prefs;
136a137,143
 >         // sets the image type based on user pref, defaults to 'png'
 >         if($prefs->getValue('im_type')!='') {
 >             $im_type = $prefs->getValue('im_type');
 >         } else {
 >             $im_type = 'png';
 >         }
 >
138c145
<             return Horde_Image::singleton('im');
---
 >             return Horde_Image::singleton('im',array( 'type' => 
$im_type ));
140c147
<             return Horde_Image::singleton('gd');
---
 >             return Horde_Image::singleton('gd',array( 'type' => 
$im_type ));


[root at space config]# diff prefs.php prefs.php.dist
30,31c30
<     'members' => array('listtype', 'showdefaultimages', 
'imagesperrow', 'imagesperpage', 'im_type',
<                        'watermark', 'auto_watermark')
---
 >     'members' => array('listtype', 'showdefaultimages', 
'imagesperrow', 'imagesperpage')
131,156d129
<
< $_prefs['im_type'] = array(
<     'value' => 'png',
<     'locked' => false,
<     'shared' => false,
<     'type' => 'enum',
<     'enum' => array('png' => _("PNG"),
<                     'jpeg' => _("JPEG")),
<     'desc' => _("Image format for converted images (thumbnail and 
screen resolutions)")
< );
<
< $_prefs['watermark'] = array(
<     'value' => '',
<     'locked' => false,
<     'shared' => false,
<     'type' => 'text',
<     'desc' => _("Watermark to use for images")
< );
<
< $_prefs['auto_watermark'] = array(
<     'value' => false,
<     'locked' => false,
<     'shared' => false,
<     'type' => 'checkbox',
<     'desc' => _("Automatically watermark all images")
< );