Added exit-on-error flag. Its value is false by default.
Added shouldStopSync function. It determines whether a sync process should be stopped or not. It does not ignore the errors AccessDenied and NoSuchBucket regardless of the value of exit-on-error flag.
sync command stops if an error is received when listing objects from source or destination when the exit-on-error flag is true. But it always ignores the ErrNoObjectFound error.
Resolves #564
Changes are made:
exit-on-errorflag. Its value isfalseby default.shouldStopSyncfunction. It determines whether a sync process should be stopped or not. It does not ignore the errorsAccessDeniedandNoSuchBucketregardless of the value ofexit-on-errorflag.synccommand stops if an error is received when listing objects from source or destination when theexit-on-errorflag istrue. But it always ignores theErrNoObjectFounderror.