Add "Icon Size" option + small l10n fixes

[1280px]

• Added option to change icons size! (small, medium, large or huge; medium by default)
• Removed unnecessary spaces in original strings; improved Russian translation
• Small consistency fixes for some margins

[Vistaus]

Or you could've pinged the original translators to update their translation, of which I am one…

[1280px]

You're right, I think I'll just remove l10n changes for languages other than English and Russian.