Add distributed lock manager singlestat files

[joehandzik]

Signed-Off-By: Joe Handzik joseph.t.handzik@hpe.com

[joehandzik]

@roclark Please take a look when you have a moment. The highlights:

1. Applied some really light heuristics to clean up the OST name (as I type that, should we change that label to "OST" rather than "OSS"?)
2. Created the directoryDepth concept, to deal with the fact that some of the ldlm elements are an extra directory level away.

Suggestions are always appreciated, feel free to merge it yourself if you're ok with the changes.

[roclark]

Everything looks good to me.

On your point about changing OSS to OST, after another look, yes, I agree with you. We will also want to change MGS -> MGT, MDS -> MDT.