replacement code for formatter & admin patch

Hello stella

As i told you this is the code i was working on.
While i started to add a new feature (download original link), i recognized some problems with argument codes and then i've been stumbled upon a lot of things. Finally i decided to rearrange a lot of code for consistency.

This is the full list done in the file:
- original image download link in lightbox, configurable, variable for text, added generic link separator
- restructured processes in theme rendering: title, caption, details
- using field_name instead of field... where field is NO array
- image alt now contains title if it was empty
- $item usage only for item data, not for formatting and output rendering options. This has been corrected after looking into many others' contributions. Misusing $item as a injection into formatters is strictly wrong. added $args where needed
- at least 4 situations less where php would alert about undefined variables.
- strict variable naming if one changes format (such as $attributes_html = drupal_attributes($attributes); ) i changed a few variables to improve understanding of code

I'd suggest also you to update the readme.txt and add i18n variable definitions if people want to translate them:
lightbox2_node_link_text
lightbox2_original_link_text
lightbox2_image_count_str
lightbox2_page_count_str
see details at http://drupal.org/node/83514

I've tested things as much as possible, but since this is a rewrite you possibly shouldn't release it as a one-step pass as stable. We need some people to check if everything still works fine.

See the file attached:
lightbox2.formatter.inc_.rewrite.zip
(i've had issues with uploading this file, hope it works!)

Thanks a lot for all feedbacks...