update plugin readability-related option names

plugins/af_readability/init.php

@@ -87,7 +87,7 @@ class Af_Readability extends Plugin {
 			print "<fieldset>";
 			print "<label class='checkbox'> ";
 			print_checkbox("enable_share_anything", $enable_share_anything);
-			print " " . __("Use Readability for pages shared via bookmarklet.");
+			print " " . __("Provide full-text services to core code (bookmarklets) and other plugins");
 			print "</label>";
 			print "</fieldset>";
 

plugins/af_redditimgur/init.php

@@ -57,7 +57,7 @@ class Af_RedditImgur extends Plugin {
 		print "<fieldset class='narrow'>";
 		print "<label class='checkbox'>";
 		print_checkbox("enable_readability", $enable_readability);
-		print " " . __("Extract missing content using Readability") . "</label>";
+		print " " . __("Extract missing content using Readability (requires af_readability)") . "</label>";
 		print "</fieldset>";
 
 		print "<fieldset class='narrow'>";