Added blue theme: FS#3223 - Blue version of default theme

interface/web/themes/blue/css/styles.css

interface/web/themes/blue/icons/x32_sprite.png

interface/web/themes/blue/images/ajax-loader.gif

interface/web/themes/blue/images/header_bg.png

interface/web/themes/blue/images/lists_tfoot_bg.png

interface/web/themes/blue/images/lists_thead_bg.png

interface/web/themes/blue/ispconfig_version

interface/web/themes/blue/templates/main.tpl.htm