Internalize external resources

[bernhardreiter]

We want to be stand-a-lone, so that no information leaks about usage
(and of course there is no way to insert information from an external server).

index.html :

• <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.5.0/css/font-awesome.min.css">
• <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/ionicons/2.0.1/css/ionicons.min.css">

AdminLTE:

• ./static/css/AdminLTE.min.css:@import url(https://fonts.googleapis.com/css?family=Source+Sans+Pro:300,400,600,700,300italic,400italic,600italic);/
  which draws in
  src: local('Source Sans Pro Light'), local('SourceSansPro-Light'), url(https://fonts.gstatic.com/s/sourcesanspro/v9/toadOcfmlt9b38dHJxOBGDRVvBvQIc1z78c__uoBcyI.woff2) format('woff2');