Fixed an issue where checking for files was slow

Don't sha1 every file before we know if we need it.

Change-Id: I8adcc869113b8ad84269450121ad1ba73267fb54
Merge "Fixed an issue where checking for files was slow"
blobserver: simplify NoImplStorage code

Change-Id: Icc133667b5038783609082ec412f7fca7ecce927
camput: add --blobdir=discard debug option

Does a dry-run and just shows the final blobref, without writing data anywhere.

Change-Id: Ia234b642b5b9029ee4fd9c61bc7edcdcfa5ca858