Fix the calls to the old getTranslation() and getAttributeTranslation() methods from SimpleSAML_XHTML_Template.

Restore the rest of the public methods in SimpleSAML_XHTML_Template that were removed, make them wrappers of the new methods, and mark them as deprecated.

Restore SimpleSAML_XHTML_Template::getLanguageCookie() and setLanguageCookie() temporarily, as wrappers over the new methods in SimpleSAML\Locale\Language.

More bugfixes. includeLanguageFile() has been moved from SimpleSAML_XHTML_Template to SimpleSAML\Locale\Translate.

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.

Add a method SimpleSAML_XHTML_Template::getTranslator() to retrieve the SimpleSAML\Locale\Translate instance local to the template, and use it to fix a bug in a template of the consent module.

Bugfix. The consentAdmin module was still calling SimpleSAML_XHTML_Template::getTag(), while that method has been moved to \SimpleSAML\Locale\Translate.

Rename \SimpleSAML\Locale\Translate::t_not_translated() to the more concise (and camel caps) getStringNotTranslated().

Return lang_merge() to SimpleSAML_XHTML_Template, as it was public, and mark it as deprecated. Use array_merge_recursive() instead.

Rename \SimpleSAML\Locale\Translate::getTranslation() to the more comprehensive \SimpleSAML\Locale\Translate::getPreferredTranslation().

Candidate for removal/rewrite

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.

This will invoke a more convenient on screen keyboard on mobile
devices and give some syntax validation as a bonus.

Try with "composer update" instead of "composer install". The latter does not support --prefer-lowest.