update site_settings language dropdown to use django's available languages
version bump
added ProfileLanguageMiddleware to assign user language to session / cookie accordingly
reorder middlewares to meet django's requirement for LocalMiddleware
set USE_I18N to False as default to reduce the unnecessary load for sites not using the internationalization machinery
update tendenci blog url
update ProfileLanguageMiddleware to check site setting localizationlanguage as well
version bump to 5.1.378
Merge branch 'master' into 943_jquery2_update

Conflicts:
	tendenci/core/site_settings/settings.json