Build support when cross-compiling.  Fix for https://bugzilla.novell.com/show_bug.cgi?id=661054
fix compilation under NET_2_0
ifdef 4.0 using
Fix System.Web.Routing test build.
Fix make check PROFILE=net_2_0 in System.Runtime.Serialization.
Fix tests compilation
Fix make check PROFILE=net_3_5 in Microsoft.Build.Tasks.
Merge pull request #465 from symform/cross-compile-support

Build support when cross-compiling.