Hugo has been making this warning for a while
WARN found no layout file for "html" for kind "term": You should
create a template file which matches Hugo Layouts Lookup Rules for
this combination.
This turned out to be the addition of the `groups:` keyword to the
command frontmatter. Hugo is doing something with this keyword though
this isn't documented in the frontmatter documentation.
The fix was removing the `groups:` keyword from the frontmatter since
it was never used by hugo.
Currently rclone check supports matching two file trees by sizes and hashes.
This change adds support for SUM files produced by GNU utilities like sha1sum.
Fixes#1005
Note: checksum by default checks, hashsum by default prints sums.
New flag is named "--checkfile" but carries hash name.
Summary of introduced command forms:
```
rclone check sums.sha1 remote:path --checkfile sha1
rclone checksum sha1 sums.sha1 remote:path
rclone hashsum sha1 remote:path --checkfile sums.sha1
rclone sha1sum remote:path --checkfile sums.sha1
rclone md5sum remote:path --checkfile sums.md5
```
