Use guarded path for obsolete files (bug 1060634)

- Update model file_path method
- Add test
Commit from Mozilla Verbatim by user yfdyh000.: 1984 of 1984 strings translated (0 fuzzy).
fix tests
Merge branch 'master' of ssh://github.com/mozilla/zamboni
Commit from Mozilla Verbatim by user kohei.yoshino@gmail.com.: 1984 of 1984 strings translated (0 fuzzy).
Commit from Mozilla Verbatim by user petercpg@mail.moztw.org.: 1984 of 1984 strings translated (0 fuzzy).
Commit from Mozilla Verbatim by user cesperanc@.: 1984 of 1984 strings translated (0 fuzzy).
script to help marketplace pre-load onto gaia
document logout endpoint (bug 1075234)
fix typo in auth docs
update login modal for fxa (bug 1051889)
fix login modal typo
Commit from Mozilla Verbatim by user besnik@programeshqip.org.: 1859 of 1984 strings translated (0 fuzzy).
Commit from Mozilla Verbatim by user inma610.: 1854 of 1854 strings translated (0 fuzzy).
"fixed" test
Merge pull request #2610 from JaredKerim-Mozilla/1060634

Use guarded path for obsolete files (bug 1060634)
Add author search to search API (bug 1032828)