[Review-3-6] Branding & Splash screen fix

[Stefan Knorr (Astron)]

Hello there,

It'd be great if someone could cherry-pick the following  two commits into 3.6:
http://cgit.freedesktop.org/libreoffice/core/commit/?id=151400ef49a2a351c236753e7e72781412659126
http://cgit.freedesktop.org/libreoffice/core/commit/?id=8b8e611e9e17d55c49209f02f70c4a0acd2e0448

(The first one updates the splash screen to use the real community
logo lockup, the second one fixes the bug on Mac OS X, where the
progress bar o nthe splash seemed very out of place)

Astron.