added precisions regarding the executable attribute in the <exec/> task

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@274989 13f79535-47bb-0310-9956-ffa450edef68

docs/manual/CoreTasks/exec.html

@@ -44,7 +44,14 @@ Notes</i>).
   <tr>
     <td valign="top">executable</td>
     <td valign="top">the command to execute without any command line
-      arguments.</td>
+      arguments.<br/>
+      <i>There is no resolution of this attribute against the build file location.</i><br/>
+      So you can use here :
+      <ul>
+      <li>the basename of the command if it is in the path (for instance <code>ls</code>),</li>
+      <li>the full path of the command (for instance <code>/usr/local/bin/emacs</code>),</li>
+      <li>a path relative to the running directory of ant.</li>
+      </ul></td>
   </tr>
   <tr>
     <td valign="top">dir</td>