Declared a helper for dealing with mounting file systems.
Declared a helper for dealing with mounting file systems.

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