stinst: Fix an inifinite recursion while printing ProxyNamespace

2013-08-10  Gwenael Casaccio <gwenael.casaccio@gmail.com>

	* STLoaderObjs.st: Fix ProxyNamespace>>#printOn: and add ProxyNamespace>>#examineOn:.
	* STLoaderObjsTests.st: Add testcase for ProxyNamespace>>#printOn:.