Move scheduler code out of plugin directory.

This moves plugin/pkg/scheduler to pkg/scheduler and
plugin/cmd/kube-scheduler to cmd/kube-scheduler.

Bulk of the work was done with gomvpkg, except for kube-scheduler main
package.

pkg/scheduler/api/validation/validation.go

@@ -0,0 +1,50 @@
+/*
+Copyright 2015 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package validation
+
+import (
+	"fmt"
+
+	utilerrors "k8s.io/apimachinery/pkg/util/errors"
+	schedulerapi "k8s.io/kubernetes/pkg/scheduler/api"
+)
+
+// ValidatePolicy checks for errors in the Config
+// It does not return early so that it can find as many errors as possible
+func ValidatePolicy(policy schedulerapi.Policy) error {
+	var validationErrors []error
+
+	for _, priority := range policy.Priorities {
+		if priority.Weight <= 0 || priority.Weight >= schedulerapi.MaxWeight {
+			validationErrors = append(validationErrors, fmt.Errorf("Priority %s should have a positive weight applied to it or it has overflown", priority.Name))
+		}
+	}
+
+	binders := 0
+	for _, extender := range policy.ExtenderConfigs {
+		if len(extender.PrioritizeVerb) > 0 && extender.Weight <= 0 {
+			validationErrors = append(validationErrors, fmt.Errorf("Priority for extender %s should have a positive weight applied to it", extender.URLPrefix))
+		}
+		if extender.BindVerb != "" {
+			binders++
+		}
+	}
+	if binders > 1 {
+		validationErrors = append(validationErrors, fmt.Errorf("Only one extender can implement bind, found %v", binders))
+	}
+	return utilerrors.NewAggregate(validationErrors)
+}