Backed out 2 changesets (bug 784739) because of Windows build failures

Backed out changeset 06ae36377cfa (bug 784739)
Backed out changeset e56f91d780df (bug 784739)
Backed out 6 changesets (bug 843829, bug 845862) because of broken mochitest-5

Backed out changeset 1df3bdadb7ce (bug 843829)
Backed out changeset 64f001fe04fb (bug 843829)
Backed out changeset 57652d8f0827 (bug 843829)
Backed out changeset 2e889cd77a48 (bug 843829)
Backed out changeset 97d16e7beb27 (bug 843829)
Backed out changeset 6c6ab0e54917 (bug 845862)

Landed on a CLOSED TREE