both whereis and metadata accept --key, --all, and --unused; document that

doc/git-annex-metadata.mdwn

@@ -66,6 +66,19 @@ When run without any -s or -t parameters, displays the current metadata.
   Enable JSON output. This is intended to be parsed by programs that use
   git-annex. Each line of output is a JSON object.
 
+* `--all`
+
+  Specify instead of a file to get/set metadata on all known keys.
+
+* `--unused`
+
+  Specify instead of a file to get/set metadata on
+  files found by last run of git-annex unused.
+
+* `--key=keyname`
+
+  Specify instead of a file to get/set metadata of the specified key.
+
 # EXAMPLES
 
 To set some tags on a file and also its author:

doc/git-annex-whereis.mdwn

@@ -32,6 +32,19 @@ For example:
   The [[git-annex-matching-options]](1)
   can be used to specify files to act on.
 
+* `--key=keyname`
+
+  Show where a particular git-annex key is located.
+
+* `--all`
+
+  Show whereis information for all known keys.
+
+* `--unused`
+
+  Show whereis information for files found by last run of git-annex unused.
+
+
 # SEE ALSO
 
 [[git-annex]](1)