Update Polish translation

Update Polish translation.
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Date: 30.04.2013

Changelog:
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* Added:
kitError2 (216)
kitNotFound (536)
socialSpy (537)
setBal (538)
insufficientFunds (540)

* Fixed:
backUsageMsg (21)
banFormat (28)
bedMissing (30)
connectedPlayers (58)
downloadingGeoIp (91)
fullStack (125)
geoIpUrlEmpty (131)
geoIpUrlInvalid (132)
healOther (148)
itemSpawn (200)
jailReleased (206)
jailSentenceExtended (208)
jailSet (209)
kickedAll (213)
kitInvFull (221)
kitOnce (222)
markMailAsRead (239)
matchingIPAddress (242)
messageTruncated (246)
nickChanged (272)
removed (376)
repairNone (381)
teleportAll (419)
tempBanned (434)
thunderDuration (437)
timeSet (442)
totalWorthAll (446)
totalWorthBlocks (447)
tradeSignEmpty (450)
youAreHealed (520)
youHaveNewMail (521)
balanceOther (527)