Add option to search on specific keycode (#37)

* Add keycode in options

trigger only search when keycode specified, for example { keyCode : 13 } for enter  event

* Add keycode in options

trigger only search when keycode specified.
for example using enter event :

$('input#search').quicksearch('table tbody tr', {
	'delay': 100,
	'selector': 'th',
	'stripeRows': ['odd', 'even'],
	'loader': 'span.loading',
	'noResults': 'tr#noresults',
	'bind': 'keyup keydown',
	'minValLength': 2,
	'removeDiacritics': true,
        'keyCode ': 13,
	'onBefore': function () {
		console.log('on before');
	},
	'onAfter': function () {
		console.log('on after');
	},
	'onValTooSmall': function (val) {
		console.log('value ' + val + ' is too small');
	},
	'show': function () {
		$(this).addClass('show');
	},
	'hide': function () {
		$(this).removeClass('show');
	}
	'prepareQuery': function (val) {
		return new RegExp(val, "i");
	},
	'testQuery': function (query, txt, _row) {
		return query.test(txt);
	}
});

src/jquery.quicksearch.js

@@ -10,6 +10,7 @@
 			caseSensitive: false,
 			noResults: '',
 			matchedResultsCount: 0,
+			keyCode : false,
 			bind: 'keyup search input',
 			resetBind: 'reset',
 			removeDiacritics: false,
@@ -315,10 +316,19 @@
 		this.loader(false);
 
 		return this.each(function () {
-			$(this).on(options.bind, function () {
-				val = $(this).val();
-				self.trigger();
+			$(this).on(options.bind, function (e) {
+				if (options.keyCode) {
+					var keycode = e.keyCode || e.which;
+					if (keycode === options.keyCode) {
+						val = $(this).val();
+						self.trigger();
+					}
+				} else {
+					val = $(this).val();
+					self.trigger();
+				}
 			});
+
 			$(this).on(options.resetBind, function () {
 				val = '';
 				self.reset();