FontAwesome 5

Closes #982 (closed)

Replaces all icons with FA5 counterparts. Removes Fontello

Some icons changed to a (slightly) different icon:

• All spinners were changed to circle-notch since FA doesn't have any spinners beyond 7-dots and circle-notch ones.
• bell-ringing is instead a frankenstein of bell and two rss icons to simulate ringing, since bell-on is a FA PRO icon :/
• Video icon (in hidden attachment placeholder) uses generic camera
• Poll icon uses horizontal poll icon, i.e. similar to graph but horizontal and inside a square.
• Smile icon uses beam version, i.e. it does the ^_^ expression. Because people complained that plain :) "stares at them"
• Smile icon in post form changed to filled variant for better harmony with other icons
• globe is changed to a generic "basketball"
• lock now has shackle turned over for better accessibility
• ellipsis in usercard is vertical instead of horizontal
• version tab in settings is now information without circle.
• notifications tab in settings is non-ringing bell
• maybe more i can't remember.

Some small bugfixes:

• Icons in navbar have been readjusted
• Icons in user-card have been readjusted and given MUCH bigger hitbox + better hover indication.
• Some components like RetweetButton have been refactored.
• Some components's CSS was changed to fit better with our guidelines.

build/webpack.base.conf.js

@@ -3,7 +3,6 @@ var config = require('../config')
 var utils = require('./utils')
 var projectRoot = path.resolve(__dirname, '../')
 var ServiceWorkerWebpackPlugin = require('serviceworker-webpack-plugin')
-var FontelloPlugin = require("fontello-webpack-plugin")
 
 var env = process.env.NODE_ENV
 // check env & config/index.js to decide weither to enable CSS Sourcemaps for the
@@ -94,15 +93,6 @@ module.exports = {
     new ServiceWorkerWebpackPlugin({
       entry: path.join(__dirname, '..', 'src/sw.js'),
       filename: 'sw-pleroma.js'
-    }),
-    new FontelloPlugin({
-      config: require('../static/fontello.json'),
-      host: 'https://fontello.com',
-      name: 'fontello',
-      output: {
-        css: 'static/[name].' + now + '.css',  // [hash] is not supported. Use the current timestamp instead for versioning.
-        font: 'static/font/[name].' + now + '.[ext]'
-      }
     })
   ]
 }