Bug 986662 - Delete tests
Bug 986662 - Delete app object methods
Merge pull request #18192 from Moz-TedC/bug981938-redux

Bug 981938: Remove INDEX_ID entry. Instead, use sync() to fetch keys from the DataStore and store them in a list in an IndexedDB. r=arthurcc
Merge pull request #18370 from viorelaioia/bug_986662_v1.4

[v1.4] Bug 986662 - Delete some redundant tests
bug 993378, add more languages to expose to testing
Merge pull request #18393 from TheoChevalier/bug993378-new-languages-for-testing

bug 993378, add more languages to expose to testing