fix build on mono

In my environment, /nostdlib will not be able to locate mscorlib. On mono,
these effectively negate each other, so best just to remove the /nostdlib
option and let it use the built in mscorlib anyway


git-svn-id: https://svn.apache.org/repos/asf/incubator/npanday/trunk@1619654 13f79535-47bb-0310-9956-ffa450edef68