Double -> Decimal

Fixed
Merge branch 'master' of https://github.com/A307/BiddingAgent

Conflicts:
	BiddingAgent/BiddingAgent.cs
	BiddingAgent/MainWindow.xaml.cs
	BiddingAgent/bin/Debug/BiddingAgent.exe
	BiddingAgent/bin/Debug/BiddingAgent.pdb
	BiddingAgentTests/PriceEstimationTests.cs