bindusg.adb: Add line for @<response file> Add lines for new switches -R and -Z

bindusg.adb: Add line for @<response file> Add lines for new switches -R and -Z

2007-04-20  Vincent Celier  <celier@adacore.com>

	* bindusg.adb: Add line for @<response file>
	Add lines for new switches -R and -Z

	* gnatbind.adb (Gnatbind): Do not include sources from the GNAT
	hierarchy in the list of files of the closure when -R is used
	(Gnatbind): Accept arguments starting with '@' to indicate response
	files and take the arguments from the response files.
	If List_Closure is set, display the referenced files

From-SVN: r125387