some plugins that need SHA1

Bundle/IkiWiki/Extras.pm

@@ -16,6 +16,7 @@ perl -MCPAN -e 'install Bundle::IkiWiki::Extras'
 
 =head1 CONTENTS
 
+Digest::SHA1
 Authen::Passphrase
 Search::Xapian
 RPC::XML

doc/plugins/graphviz.mdwn

@@ -37,3 +37,5 @@ Some example graphs:
 [[graph src="a -> b -> c; a -> b;"]]
 [[graph src="a -- b -- c -- a;" prog="circo" type="graph"]]
 """]]
+
+This plugin uses the [[cpan Digest::SHA1]] perl module.

doc/plugins/sparkline.mdwn

@@ -20,6 +20,8 @@ to use the plugin, you will need:
 On a Debian system, this can be accomplished by installing these packages:
 `libsparkline-php` `php5-gd` `php5-cli` `libdigest-sha1-perl`
 
+This plugin also uses the [[cpan Digest::SHA1]] perl module.
+
 # examples
 
 	\[[sparkline 1 3 5 -3 10 0 width=40 height=16