Bug 120150 - add tooltip to Send Later button. r=stephend/racham/jglick/robin; sr=sspitzer.

mailnews/compose/resources/content/messengercompose.xul

@@ -362,7 +362,7 @@
                now_label="&sendButton.label;"
                now_tooltiptext="&sendButton.tooltip;"
                later_label="&sendLaterCmd.label;"
-               later_tooltiptext="">
+               later_tooltiptext="&sendlaterButton.tooltip;">
         <observes element="Communicator:WorkMode" attribute="offline"/>
        </toolbarbutton>
        <toolbarseparator class="toolbarseparator-primary"/>

mailnews/compose/resources/locale/en-US/messengercompose.dtd

@@ -174,6 +174,7 @@
 <!ENTITY addressBar.tooltip "Address Bar">
 <!ENTITY formatToolbar.tooltip "Formatting Toolbar">
 <!ENTITY sendButton.tooltip "Send this message now"> 
+<!ENTITY sendlaterButton.tooltip "Send this message later"> 
 <!ENTITY quoteButton.tooltip "Quote the previous message"> 
 <!ENTITY addressButton.tooltip "Select a recipient from an Address Book"> 
 <!ENTITY attachButton.tooltip "Attach a file to this message">