More bugfixes. The SimpleSAML\Locale\Language::$languageParameterName and SimpleSAML\Locale\Language::$language properties should be private, and therefore not accessed from the outside of their respective classes. Add getters instead.

A template now has a translator-object, SimpleSAML_Locale_Translate.
This handles the existing translation system.

The translator has a language-object, SimpleSAML_Locale_Language. This
handles discovery and switching of locale.

SimpleSAML_XHTML_Template has several methods that are wrapped
translator-methods:

t()
isLanguageRTL()
getLanguageList()
getTranslation()

This way it isn't necessary to change much of the existing system.