stinst: Introduce a RBNumberLiteralToken to keep numbers in the original format

When using gst-convert to convert code number literals were rewritten from
forms like 2r01 to 1. In most cases this is not wanted because the bits might
come from a specification or make it more obvious what one tests for.

2013-02-08  Holger Hans Peter Freyther  <holger@freyther.de>

	* RBFormatter.st: Use the RBToken>>#storeOn: for writing.
	* RBParser.st: Create a RBNumberLiteralToken for number literals.
	* RBToken.st: Create the RBNumberLiteralToken class.
	* RewriteTests.st: Add test for the number literal parsing
	* package.xml: Add the new test to the testsuite.