Custom CSS tweaks for Firefox v4.1.3pre

[Buttons]

• (fix) custom icon options > downloads button > size
• (tweak) custom icon options > downloads button > restored default progress animation
• (removed) custom icon options > hide downloads buttons badge
• (fix) custom back/forward buttons appearance > connected

[Tabs]

• (fix) Fx97+: classic squared tabs size

[about:addons]

• (fix) Fx97+: show buttons instead of popup options