Prepend Project Path to GOPATH, catch TestConfiguration Exception.

The TestConfiguration readExternal throw serialization Exception, and I can't address the real issue, but just catch the exception seems works fine. 

I noticed that the test config xml element in `workspace.xml` is different. there has an <option name="module"><Module/></option> element in it, and other runner configuration element do not have it.

And for Go Install Compiler, I changed to prepend project path to GOPATH, so the packages in original GOPATH can be imported.

And the GoSdkUtil prependPath method should call System.getenv to get GOPATH.