Renamed to ReadProxy and defined the purpose.
Renamed to ReadProxy and defined the purpose.

kahing/gcsfuse,GoogleCloudPlatform/gcsfuse,BanzaiMan/gcsfuse,jacobsa/ratelimit,mbrukman/gcsfuse,GoogleCloudPlatform/gcsfuse,jacobsa/timeutil,BanzaiMan/gcsfuse,GoogleCloudPlatform/gcsfuse