Script updates + directory structure cleanup

-Updated JQuery to v3.5.1
-Updated Bootstrap to v4.5.3
-Updated DataTables to v1.10.22
-Updated FontAwesome to v5.15.1
-Updated Chart.js to v2.9.4
-Updated flag-icon-css to v3.5.0
-All scripts now load minified
-Removed unused/unnecessary scripts (moment.js and some jqPlot plugins)
-Scripts that are not used on every page are now only loaded on pages where they are needed (jqPlot, Chart.js and flag-icon-css)
-Default website language to English
-Enable unicode support
-Removed unused images
-public directory cleanup (images directory renamed to img, javascript directory renamed to js, stylesheets directory renamed to css, themes directory moved from /public/themes to /public/css/themes, removed vendor directory and moved the important contents to the new img, css and js directories)
-Reward.pug rewritten to support Chart.js v2.9.4
-Updated README Features section

package.json

@@ -6,7 +6,7 @@
     "start": "npm run sass:compile && node --stack-size=10000 ./bin/cluster",
     "stop": "kill -2 $(cat tmp/cluster.pid)",
     "test": "node ./node_modules/jasmine/bin/jasmine.js",
-    "sass:compile": "sh ./scripts/sass_theme_reader.sh && ./node_modules/.bin/sass --no-source-map --style=compressed ./public/stylesheets/style.scss ./public/stylesheets/style.min.css"
+    "sass:compile": "sh ./scripts/sass_theme_reader.sh && ./node_modules/.bin/sass --no-source-map --style=compressed ./public/css/style.scss ./public/css/style.min.css"
   },
   "dependencies": {
     "express": ">=4.17.1",