Show right messages as soon as possible

[x4base]

1. Flashed messages should be flushed in every single page, otherwise they will be accumulated and shown in the wrong page, making the users extremely confused.
2. The error messages of API calls should be shown immediately, and should not flash any message, because it will always be shown in the wrong page.

[coveralls]

Coverage remained the same at 81.941% when pulling 4ed6475 on x4base:ajax_error_messages into 04388a7 on airbnb:master.

[coveralls]

Coverage increased (+0.1%) to 82.077% when pulling f1ce77e on x4base:ajax_error_messages into 04388a7 on airbnb:master.

[mistercrunch]

I think this belongs in caravel.js or utils.js

[x4base]

I can move showApiMessage() and toggleCheckbox() into utils.js.
But we still need to include some .entry.js in list.html, right? Should I still include global_functions.entry.js (or maybe rename it to list.entry.js) and call util.toggleChekbox() in this file? Or do you have any other idea?

[x4base]

Or are you only talking about the line you mentioned? I only have to replace

var $ = window.$ = require('jquery');
var jQuery = window.jQuery = $;

with

var $ = require('jquery');

, just don't touch the window variable, right?

[x4base]

I've just found out it shouldn't be in list.html, otherwise the script will be included multiple times if there are multiple inline list views. For example, in the datasource edit page, there are column list tab and metric list tab, so the script will be included twice. I think it should be in base.html, so I named it common.entry.js

[coveralls]

Coverage increased (+0.08%) to 82.019% when pulling 2b92e3a on x4base:ajax_error_messages into 04388a7 on airbnb:master.