internationalisation: tabs module

[christoph]

element vars of ids are now php vars (because they are needed in SQL)

UPDATE gui_element_vars SET var_type = 'php_var' WHERE fkey_e_id = 'tabs' AND var_name LIKE 'tab_ids%'

delete tab titles (now e_title in gui_element)

DELETE FROM gui_element_vars WHERE fkey_e_id = 'tabs' AND var_name LIKE 'tab_titles%'