add IsAny=true support for DataContractSerializer
[build/msbuild] Tool resolves assemblies based on exact match, not random-last
Don't define _XOPEN_SOURCE on OpenBSD. With _XOPEN_SOURCE defined mincore() is not visible.

This change is licensed under the MIT license.
Merge pull request #1051 from josedonizetti/bug11916-DataContractSerializer

add IsAny=true support for DataContractSerializer
[mcs] Handling of nested effective base classes
Fix WebProxy.BypassProxyOnLocal logic.
[mcs] Expand type parameter member change using effective base type
Fix tests not to hang on failure
Merge pull request #1052 from sethjackson/master

Don't define _XOPEN_SOURCE on OpenBSD.
Revert "Fix WebProxy.BypassProxyOnLocal logic."

This reverts commit 3f7ad8f457f67576f400a172573081818fbda2dc.

WebProxy.BypassProxyOnLocal is really broken!  There seems to be no
way of actually bypassing a proxy on local connections.
Small fix.
[MS.Build] fix default build targets to not return empty list in Project.

And since the code is almost the same as existing ProjectInstance one, just
make it identical. (Should be unified, but depends on members, hence TODO.)
[MS.Build] fix some TaskFactory related bugs uncovered by CodeTaskFactory impl.

- ITaskFactory could return null, so check the return value.
- UsingTask descendants could have property references, so use ExpandString.
- TaskBody was not appropriately passed to internal structure.
[msbuild] implement CodeTaskFactory i.e. inline tasks.
[system] Small optimization for Xamarin.Mac (where we know we're executing on a Mac)