language display name for the language set by the constructor
This class maintains state of the selected language and can set the language.
getLocalisedValue(mixed|string|int valueArray) :
pick a proper value for a given language
an array of (locale,content) records
localised value corresponding to the chosen locale or to the defalut locale C if a better mach was not available
set_lang does all language setting magic checks if lang has been declared in the http call if not, checks for saved lang in the SESSION or finally checks browser properties.
Only one of the supported langiages can be set if a match is not found, the default langiage is used