fix(parser): make sure toNumber and toBoolean can be turned off

* toBoolean and toNumber change.

I tried to use:
var qs = new MongoQS({
	string: {
		toNumber: false
	}
});

But toNumber and toBoolean is always in true.
I propose a change so firstly it checks if it is boolean and then makes the change.

Thanks for this great module! :)

* Fix without ( and ) in typeof

* Strings changed to singlequoted for test pass

Author: lucaskenda

index.js

@@ -12,8 +12,8 @@ module.exports = function MongoQS(options) {
   // String Value Parsing
   opts.string = opts.string || {};
   this.string = opts.string || {};
-  this.string.toBoolean = opts.string.toBoolean || true;
-  this.string.toNumber = opts.string.toNumber || true;
+  this.string.toBoolean = (typeof opts.string.toBoolean === 'boolean') ? opts.string.toBoolean : true;
+  this.string.toNumber = (typeof opts.string.toNumber === 'boolean') ? opts.string.toNumber : true;
 
   this.keyRegex = opts.keyRegex || /^[a-zæøå0-9-_.]+$/i;
   this.valRegex = opts.valRegex || /[^a-zæøå0-9-_.* ]/i;