mdtest options not documented in man page

[rfmohr]

As I was looking through the mdtest source, I noticed several options that did not appear to be documented in the man page: -a: supported APIs -k: use mknod to create files -P : print rate and time -W: number in seconds; stonewall timer -x: StoneWallingStatusFile -X,--verify-read: Verify the data read --verify-write: Verify data after a write -y: sync file after writing -Y: call sync after each phase -Z: print time instead of rate --warningAsErrors: any warning should lead to an error

Also (when verbose >=1), the section that prints out the current option values doesn't seem to include the following:

branch_factor remove_only print_rate_and_time randomize stoneWallingStatusFile verify_read verify_write print_time

I know the output lists the command line and options that were invoked, but for consistency it might be good to include the above option values as well.