Removed Redundant method validate(String string)

removed following redundant method as in Test.java we are calling validator.validate(string, false);

	public boolean validate(String string) {
		return validate(string, false);
	}
revoking last change

re-adding validate(String string) method
addition of new test cases 

added mathematical expression to test and used </code> validator.validate(string);</code> and created separate <code> isFormatted(boolean valid, String string) </code> method
Merge pull request #3 from exexzian/master

Added Mathematical test cases

{2+[3*4/(3-1)]} 	-> well formatted
[{2+1/(2-7)]} 	-> malformatted