Backed out changeset 6efabfb144b1 (bug 940617) for mochitest-bc failures.
Bug 931921 - Prevent creating multiple intances of global actors. r=past
Bug 941012 - Always use SDK loader to load DebuggerServer. r=jryans
Backed out 6 changesets (bug 854169) to investigate OSX Mn bustage on a CLOSED TREE.

Backed out changeset 236a0eba3a8a (bug 854169)
Backed out changeset bd7733e5d5cf (bug 854169)
Backed out changeset cbf7e38a49aa (bug 854169)
Backed out changeset c0f9bfe37d74 (bug 854169)
Backed out changeset 224d0d4df434 (bug 854169)
Backed out changeset 1b339f171b0a (bug 854169)