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
Each major interface is now in its own file. Any package private
functions that are only referenced by a particular module was also moved
to the corresponding file. All common helper functions were moved to
gce_util.go.
This change is a pure movement of code; no semantic changes were made.