Updated getlist to be multibyte safe and article update getButtons override change

currently the processor does not support any multi byte strings (Chinese under a utf8 charset) and no results return in the grid view.

Using the mb_* functions with the correct charset resolves the issue.

Also updated the update.js getButtons function to correctly load any existing buttons and replace them rather than creating there own buttons. This allows any Extras to add additional buttons to the articles page without any hacks.