#22 #23 Revamping "set" variable expansion to make it more correct.

There is now a batch file interceptor that reads and evaluates the
contents of all *.bat files. This works well, but the "set" command's
variable expansion was not working properly. This requires additional
work - see the JUnit tests in AliasInterceptorTest.java that still need
to be implemented.

As a sanity check, variable expansion is not working. Try something like
:
> set jv="java -version"
> jv