Removed system("pause") invocation before packer returns from its main()
Changed the algorithm used to filter certain system errors

Now if the error message starts with "System Error.  Code: ", that
message is parsed to obtain a numerical error code. The code is then
used to determine whether the message should be filtered.
Changed project settings

Running packer in pre-build event instead of custom build step
payload.h shouldn't be in the repo

It's an intermediate file to be packed into the final executable file.