Expression parser now uses mw::Datum instead of stx::AnyScalar in its public interface (AnyScalar is still used internally)
Made all Datum methods non-virtual.  Removed unused ImmutableData class.  Improved formatting of GenericData.h.
Improved use of const and references in Datum's interface
Expression parser functions now receive their parameters as Datum's, not AnyScalar's
stx::ParseNode::evaluate_const now takes a Datum*, instead of AnyScalar*
Finished transitioning expression parser from stx::AnyScalar to mw::Datum.  Updated mw_test to handle mangled unit test names better.
Completed removal of stx::AnyScalar
Cleaned up GenericDataTest sources
Added more test cases to GenericDataTest.  Improvements to Datum arithmetic operator, comparison operator, and stringification methods.
Use MWorks expression parser to parse VariablesWindow input values.  VariablesWindow now displays string values in enclosing quotes.
Expression parser now supports list literals (i.e. comma-separated expression lists enclosed in square brackets).  Updated formatting of boolean and list values in Datum::toString.
Fixed some tests that were failing due to unintended division by zero at load time
Restored expression parser's previous handling of numeric overflow.  Removed an obsolete test.
Datum output streaming is once again compatible with I/O manipulators
Converted MWEditor's VariableInspectorView.xib to Xcode 5 format
Variables can now have type "any", in which case the default_value string is passed directly to the expression parser, which evaluates it like any other expression, and the result is assigned to the variable as is, without any type casting.  In the editor, new variables now have type "any" by default.
Division of one boolean/integer-valued Datum by another now returns a float-valued result; consequently, all number/number division expressions now produce a floating-point result
Updated ListReplicatorDataTypes test