Update Polish tips and mission map descriptions

Update changelog regarding wrap world edge bugs

Add Polish translation for campaigns and new missions

Update pl.txt translation file

Backed out changeset c162995831d8

Backed out changeset 058a5d373e4a

Backed out changeset d08afea02908

Minor pl.txt update

Update and complete Polish frontend translation

Fix Hedgewars going into suspension mode (game freezes) when windows got minimized

Update Polish translation (frontend, 3 strings missing)

Fix broken cancel button on the login window (bug #373)

ACF6: Make sure player only gets portal gun at the portal sequence, and not a pile full of weapons and ropes

ACF3: Mention mines time in a sequence where it has been forgotten String freeze is maintained, the string is already in stub.lua

ACF2: Fix Lua error spam when Leaks A Lot died in same turn as weaklings, also do other minor tweaks - Grant skip to Dense Cloud and Leaks A Lot again, after refusing the cyborg's offer - Fix flow chart - String freeze is maintained, the new string is already in stub.lua.