Updated panels_load_include() to prevent the re-inclusion of already-loaded include files. Hackish, but eh.

by douggreen: Removed additional t() calls; added str_replace() to exporter to match coding standards.

Changed name of argument error code constants slightly; added brackets in panels_load_include() for clarity.

Forward port of the update to panels_export_display() - disappearance of the 'name' field still needs investigation.

Just need to get the delete button working and then go through all the contexts, relationships and arguments to make sure their forms are working.

Minor E_NOTICE revision; some theme_panels_* functions were concatenating into $output without declaring it first.

Initial port of panels mini; still need to work on the "context" ajax stuff and convert it to the new system, but the other stuff appears to work at least a little. Also include some fixes to layouts as "id" turns out to be illegal due to Drupal setting its own id string.

Templatize all panel layouts; give each layout its own directory for cleanliness. Slight improvement to the API needed for the move to work.

Initial D6 work -- this includes only panels.module stuff. Right now the drag & drop display editor works, layout, layout settings and render works. Special features such as cache and styles may or may not work.