Fixed #5.  Added '^' to the 'scanBinary' method of the Scanner struct.  This should complete the scanner until the first release.
Updated the Boolean.disco file.  Replaced 'or:' with '|', 'and:' with '&', and 'xor:' with '^'.  This is more inline withe the Smalltalk 80 book and the Smalltalk standard methods for True and False.