[FIX][BUG]RuleDate>>basicUpdateForMonth:year: - source fails to compile ( [cd][su] fixed for 3.7beta )

[rsbohn at rocketmail.com]

Reported as not compiling in 3.7beta. Added test cases, then fixed to
pass the test cases. Looks like this came from some other Smalltalk, one
with a julianDay based date system. Probably not back portable with my
changes as I haven't worked with other Smalltalk date classes.
This is an interesting class. Some further refactoring is possible:
clean up the code and make it more flexible. For example, it should
accept symbols instead of just strings (see RuleDate
class>>newDayOfWeek:selectionRule).

For great justice!
rsb Randall S. Bohn