fix issue95 - treat a failing pytest_genscript import

as non-critical, give a hint.

--HG--
branch : trunk

py/_test/pluginmanager.py

@@ -140,6 +140,13 @@ class PluginManager(object):
         except py.test.skip.Exception:
             e = py.std.sys.exc_info()[1]
             self._hints.append("skipped plugin %r: %s" %((modname, e.msg)))
+        except ImportError:
+            e = py.std.sys.exc_info()[1]
+            if "zlib" in str(e) and modname == "pytest_genscript":
+                self._hints.append("skipped plugin %r: failed to import %r" %(
+                    (modname, str(e))))
+            else:
+                raise
         else:
             check_old_use(mod, modname) 
             self.register(mod)