Drop the version attribute on the generator tag in Atom feeds.

Removing the version means that rebuilds are reproducible over time.

Both the generator tag and its version attribute are optional:

http://tools.ietf.org/html/rfc4287#section-4.2.4

IkiWiki/Plugin/inline.pm

@@ -677,7 +677,6 @@ sub genfeed ($$$$$@) {
 		guid => $guid,
 		feeddate => date_3339($lasttime),
 		feedurl => $feedurl,
-		version => $IkiWiki::version,
 	);
 	run_hooks(pagetemplate => sub {
 		shift->(page => $page, destpage => $page,

templates/atompage.tmpl

@@ -33,7 +33,7 @@
 <id><TMPL_VAR PAGEURL></id>
 </TMPL_IF>
 <subtitle type="html"><TMPL_VAR FEEDDESC ESCAPE=HTML></subtitle>
-<generator uri="http://ikiwiki.info/" version="<TMPL_VAR VERSION>">ikiwiki</generator>
+<generator uri="http://ikiwiki.info/">ikiwiki</generator>
 <updated><TMPL_VAR FEEDDATE></updated>
 <TMPL_VAR CONTENT>
 </feed>