Backed out 5 changesets (bug 894595) for causing new mochitest-bc intermittent failures.

Backed out changeset 778adbf10481 (bug 894595)
Backed out changeset 5b621d8eb5e9 (bug 894595)
Backed out changeset 91303ff403ac (bug 894595)
Backed out changeset 3caa785122bf (bug 894595)
Backed out changeset 108e2b8e177c (bug 894595)
Bug 910236 - The Downloads Panel shows one extra download for the number in "+ X other downloads". r=enn
Bug 906620 - Implement the taskbar indicator for downloads. r=enn
Backed out changeset 0da508ef253c (bug 896291) for mochitest-bc failures.
CLOSED TREE