Removed expr/ directoryw
	deleted:    expr/Benchmark.java
	deleted:    expr/Example.java
	deleted:    expr/Expr.java
	deleted:    expr/Parser.java
	deleted:    expr/RegressionTest.java
	deleted:    expr/Scanner.java
	deleted:    expr/SyntaxException.java
	deleted:    expr/Token.java
	deleted:    expr/Variable.java