import: make help clearer. suggested by asak.

mercurial/commands.py

@@ -1721,9 +1721,10 b' def import_(ui, repo, patch1, *patches, '
 
     You can import a patch straight from a mail message.  Even patches
     as attachments work (body part must be type text/plain or
-    text/x-patch to be used).  Sender and subject line of email
-    message are used as default committer and commit message.  Any
-    text/plain body part before first diff is added to commit message.
+    text/x-patch to be used).  From and Subject headers of email
+    message are used as default committer and commit message.  All
+    text/plain body parts before first diff are added to commit
+    message.
 
     If imported patch was generated by hg export, user and description
     from patch override values from message headers and body.  Values