Adds support for PodCIDR allocation from the GCE cloud provider

If CIDRAllocatorType is set to `CloudCIDRAllocator`, then allocation
of CIDR allocation instead is done by the external cloud provider and
the node controller is only responsible for reflecting the allocation
into the node spec.

- Splits off the rangeAllocator from the cidr_allocator.go file.
- Adds cloudCIDRAllocator, which is used when the cloud provider allocates
  the CIDR ranges externally. (GCE support only)
- Updates RBAC permission for node controller to include PATCH

pkg/controller/node/nodecontroller_test.go

@@ -101,6 +101,7 @@ func NewNodeControllerFromClient(
 		serviceCIDR,
 		nodeCIDRMaskSize,
 		allocateNodeCIDRs,
+		RangeAllocatorType,
 		useTaints,
 		useTaints,
 	)
@@ -549,9 +550,22 @@ func TestMonitorNodeStatusEvictPods(t *testing.T) {
 	}
 
 	for _, item := range table {
-		nodeController, _ := NewNodeControllerFromClient(nil, item.fakeNodeHandler,
-			evictionTimeout, testRateLimiterQPS, testRateLimiterQPS, testLargeClusterThreshold, testUnhealtyThreshold, testNodeMonitorGracePeriod,
-			testNodeStartupGracePeriod, testNodeMonitorPeriod, nil, nil, 0, false, false)
+		nodeController, _ := NewNodeControllerFromClient(
+			nil,
+			item.fakeNodeHandler,
+			evictionTimeout,
+			testRateLimiterQPS,
+			testRateLimiterQPS,
+			testLargeClusterThreshold,
+			testUnhealtyThreshold,
+			testNodeMonitorGracePeriod,
+			testNodeStartupGracePeriod,
+			testNodeMonitorPeriod,
+			nil,
+			nil,
+			0,
+			false,
+			false)
 		nodeController.now = func() metav1.Time { return fakeNow }
 		nodeController.recorder = testutil.NewFakeRecorder()
 		for _, ds := range item.daemonSets {