THRIFT-2082 Executing "gmake clean" is broken

Patch: Pavlin Radoslavov
THRIFT-1709 Warning "Bitwise-or operator used on a sign-extended operand; consider casting to a smaller unsigned type first" in TBinaryProtocol.cs at ReadInt64()

Patch: Jens Geyer
THRIFT-2080 C# multiplex processor does not catch IOException

Patch: Jens Geyer