Added a couple of comments into these property files. r=none

intl/uconv/src/charsetData.properties

@@ -18,11 +18,14 @@
 ##
 ## Contributor(s): 
 
-##
 ## Rule of this file:
 ## 1. key should always be in lower case ascii so we can do case insensitive
 ##    comparision in the code faster.
 
+## Format of this file:
+## charset_name.notForBrowser = anything  -  specifies that this charset is 
+## not to be used in the browser
+
 x-user-defined.notForBrowser = true
 t.61-8bit.notForBrowser = true
 utf-32le.notForBrowser = true

intl/uconv/src/charsetTitles.properties

@@ -18,11 +18,14 @@
 ##
 ## Contributor(s): 
 
-##
 ## Rule of this file:
 ## 1. key should always be in lower case ascii so we can do case insensitive
 ##    comparision in the code faster.
 
+## Format of this file:
+## charset_name.title = a_title  -  specifies the human readable title for 
+## this charset
+
 iso-8859-1.title = Western (ISO-8859-1)
 iso-8859-2.title = Central European (ISO-8859-2)
 iso-8859-3.title = South European (ISO-8859-3)