update legal docs
update model cache in background of builder's defer (bug 995288)
Merge pull request #465 from ngokevin/updatemodel

update model cache in background of builder's defer (bug 995288)
add new locales; bug 989950
Commit from Mozilla Verbatim by user julenx@gmail.com.: 290 of 290 strings translated (0 fuzzy).
Merge branch 'master' of github.com:mozilla/fireplace
Commit from Mozilla Verbatim by user besnik@programeshqip.org.: 289 of 290 strings translated (0 fuzzy).
Commit from Mozilla Verbatim by user umesh007.: 238 of 290 strings translated (0 fuzzy).