Add minor hints to username fields (no blanks, lowercase).

www/addusr.php3

@@ -61,7 +61,7 @@ else {
 <?php
 if ($returning) {
     echo "<tr>
-              <td>*Username (no blanks):</td>
+              <td>*Username (no blanks, lowercase):</td>
               <td class=\"left\">
                   <input type=\"readonly\" name=\"uid\" value=\"$uid\"></td>
           </tr>\n";

www/newproject_form.php3

@@ -70,7 +70,7 @@ echo "<tr>
 # UserName:
 #
 echo "<tr>
-          <td>*Username:</td>
+          <td>*Username (no blanks, lowercase):</td>
           <td class=\"left\">
               <input name=\"proj_head_uid\"";
 if ($row) {