Remove flawed touchscreen detection

https://www.fxsitecompat.com/en-CA/docs/2016/touch-event-support-has-been-re-enabled-on-windows-desktop/

assets/javascripts/lib/util.coffee

@@ -336,9 +336,6 @@ $.popup = (value) ->
     window.open value.href or value, '_blank'
   return
 
-$.isTouchScreen = ->
-  typeof ontouchstart isnt 'undefined'
-
 $.isWindows = ->
   navigator.platform?.indexOf('Win') >= 0
 

assets/javascripts/views/layout/mobile.coffee

@@ -32,9 +32,7 @@ class app.views.Mobile extends app.View
     super
 
   init: ->
-    if $.isTouchScreen()
-      FastClick.attach @body
-      app.shortcuts.stop()
+    FastClick.attach @body
 
     $.on @body, 'click', @onClick
     $.on $('._home-btn'), 'click', @onClickHome

assets/javascripts/views/search/search.coffee

@@ -41,7 +41,7 @@ class app.views.Search extends app.View
     return
 
   autoFocus: =>
-    unless $.isTouchScreen()
+    unless app.isMobile()
       @input.focus() unless document.activeElement is @input
     return
 

assets/javascripts/views/search/search_scope.coffee

@@ -95,7 +95,7 @@ class app.views.SearchScope extends app.View
     else if not @doc and @input.value
       return if event.ctrlKey or event.metaKey or event.altKey or event.shiftKey
       if event.which is 9 or # tab
-         event.which is 32 and (app.isMobile() or $.isTouchScreen()) # space
+         (event.which is 32 and app.isMobile()) # space
         @search @input.value[0...@input.selectionStart]
         $.stopEvent(event) if @doc
     return

assets/javascripts/views/sidebar/sidebar.coffee

@@ -10,7 +10,7 @@ class app.views.Sidebar extends app.View
     escape: 'onEscape'
 
   init: ->
-    @addSubview @hover  = new app.views.SidebarHover @el unless app.isMobile() or $.isTouchScreen()
+    @addSubview @hover  = new app.views.SidebarHover @el unless app.isMobile()
     @addSubview @search = new app.views.Search
 
     @search

assets/stylesheets/global/_base.scss

@@ -14,6 +14,7 @@ body {
   color: $textColor;
   word-wrap: break-word;
   overflow-wrap: break-word;
+  touch-action: manipulation;
   -webkit-tap-highlight-color: rgba(black, 0);
   -webkit-touch-callout: none;
   -webkit-text-size-adjust: 100%;