WB 2.08.x

Ticket #974 Usability bug in /preferences

fix ticket #975 some weird /pages/ header infos

show_menu2 remove unneeded code for WB < 2.7
class.wb.php, recoding backend preference
add a language variable $MESSAGE['PREFERENCES']['INVALID_CHARS']
update theme.css & preference.htt in argos_theme & wb_theme
remove classic_theme