change the LocaleTemplates at line 317 in togetherjs.js

There is a bug in file togetherjs.js: When it request the templates-en-US, I found in console it was an error "templates do not load". Using the FireBug it shows the file request "templates-en_US", so in togetherjs.js the variable LocaleTemplates at line 317 was wrong. I changed it with new "lang" in the TogetherConfig which has been changed.