It is possible to set $conf[nobase64_img] 'true' to disable embedding 
image data. For dynamically generated content, this may (slightly) 
reduce size, as the image files can be cached in the browser, rather 
than being embedded (and retransmitted) in every refresh of the page.

This advantage is not present when in the compressed stylesheets 
generated by Horde_Themes_Css_Compress, since they do not contain 
dynamic content and therefor can/will be cached in the client browser 
anyway. There is nothing to gain by not embedding the image data. In 
this case, *not* embedding image data (when possible), is actually 
detrimental to the total download size, as each image file will need 
to be downloaded separately with its own header appended (not to speak 
of the additional connections to download these files).

Therefor this patch embeds images in compressed stylesheets regardless 
of the $conf[nobase64_img] setting and only make it only depend on the 
capabilities of the client browser requesting it.