Add COM4J.wrapSta for wrapping STA com objects

[tonyroberts]

Objects wrapped in this way can only be called from the same thread they were created by (and wrapped in).

When using these wrapped objects calls to the COM object are done in the same thread instead of using a second thread. This has the disadvantage that these objects can't be passed around and used from anywhere, but where a COM object has to be called from a specific thread it means they can be used (mostly only a problem when the Java code is running in the same process as an in-process COM server).

Fixes #68