[platform-update-dev] Updated spec

[klicnik@xxxxxxxxxx]

An updated copy of the install spec is posted on eclipse.org. See the 
update component development resource page, or 
http://dev.eclipse.org/viewcvs/index.cgi/%7Echeckout%7E/platform-update-home/doc/working/eclipse_install_R2_0_draft.html

Change History: 

 *   general text cleanup 
 *   <feature><group> support removed (will not be in Eclipse 2.0) 
 *   arch= support added to <feature> and <feature><plugin> 
 *   os=/ arch=/ ws=/ nl= added to <feature><data> 
 *   <site url=""> new semantics 
 *   corrected errors in native installer link support 
 *   defined callback query strings for browser-triggered processing