Maven should factor in session close failure into build outcome

Since closeable session in Resolver 2.0, the close was implemented, but any possible failure during closing the session would "bubble up", instead to be handled.

Maven should close and also handle any error that may happen during session close operation. The build outcome ("build success" or "build failure") is evaluated WAY BEFORE repository system session is closed, and this is wrong, as build should fail if session close failed.