Change "insane" to "absurd" (referring to high fees) in text strings and identifiers.

Note that this will also require translation changes in Transifex for the key
"A fee higher than %1 is considered an insanely high fee." which is now
"A fee higher than %1 is considered an absurdly high fee."

Signed-off-by: Daira Hopwood <daira@jacaranda.org>

src/qt/walletmodel.cpp

@@ -279,9 +279,9 @@ WalletModel::SendCoinsReturn WalletModel::prepareTransaction(WalletModelTransact
             return TransactionCreationFailed;
         }
 
-        // reject insane fee > 0.1 bitcoin
+        // reject absurdly high fee > 0.1 bitcoin
         if (nFeeRequired > 10000000)
-            return InsaneFee;
+            return AbsurdFee;
     }
 
     return SendCoinsReturn(OK);