revert hammer js changes

app/assets/javascripts/post_popular.js

@@ -0,0 +1,41 @@
+(function() {
+  Danbooru.PostPopular = {};
+
+  Danbooru.PostPopular.nav_prev = function() {
+    if ($("#popular-nav-links").length) {
+      var href = $("#popular-nav-links a[rel=prev]").attr("href");
+      if (href) {
+        location.href = href;
+      }
+    }
+  }
+
+  Danbooru.PostPopular.nav_next = function() {
+    if ($("#popular-nav-links").length) {
+      var href = $("#popular-nav-links a[rel=next]").attr("href");
+      if (href) {
+        location.href = href;
+      }
+    }
+  }
+
+  Danbooru.PostPopular.initialize_all = function() {
+    if ($("#c-explore-posts").length) {
+      if (Danbooru.meta("enable-js-navigation") === "true") {
+        $(document).bind("keypress", "a", function(e) {
+          Danbooru.PostPopular.nav_prev();
+          e.preventDefault();
+        });
+
+        $(document).bind("keypress", "d", function(e) {
+          Danbooru.PostPopular.nav_next();
+          e.preventDefault();
+        });
+      }
+    }
+  }
+})();
+
+$(document).ready(function() {
+  Danbooru.PostPopular.initialize_all();
+});