Invalid return for signed bytes in GetNumberSize

[jtsylve]

SharpSerializer/SharpSerializer/Core/Binary/Elements.cs

Line 226 in 5578286

if (value < byte.MinValue || value > byte.MaxValue) return B2;

This function returns an invalid number of bytes for signed 8-bit integers. I believe the check should be referencing SByte.MinValue and SByte.MaxValue rather than byte.