frontend: Make signup/login/passwordreset/forgot forms submittable

Fixes #117

frontend/js/forgot.js

@@ -4,7 +4,9 @@
   (document);
 
   // Talks to the API and sends an reset email.
-  global.sendResetHex = function() {
+  global.sendResetHex = function(event) {
+    event.preventDefault();
+
     var allOk = global.unfilledMark(["#email"], function(el) {
       el.css("border-bottom", "1px solid red");
     });

frontend/js/login.js

@@ -43,7 +43,9 @@
 
 
   // Logs the user in and redirects to the dashboard.
-  global.login = function() {
+  global.login = function(event) {
+    event.preventDefault();
+
     var allOk = global.unfilledMark(["#email", "#password"], function(el) {
       el.css("border-bottom", "1px solid red");
     });

frontend/js/reset.js

@@ -1,7 +1,9 @@
 (function (global, document) {
   "use strict";
 
-  global.resetPassword = function() {
+  global.resetPassword = function(event) {
+    event.preventDefault();
+
     var allOk = global.unfilledMark(["#password", "#password2"], function(el) {
       el.css("border-bottom", "1px solid red");
     });

frontend/js/signup.js

@@ -4,7 +4,9 @@
   // Signs up the user and redirects to either the login page or the email
   // confirmation, depending on whether or not SMTP is configured in the
   // backend.
-  global.signup = function() {
+  global.signup = function(event) {
+    event.preventDefault();
+
     if ($("#password").val() !== $("#password2").val()) {
       global.textSet("#err", "The two passwords don't match");
       return;