Prefer use CDN for: jQuery, Bootstrap and FontAwesome, continue to use Grunt to minify app JS and CSS

Create FlatFile entity, and a CopiedFile parent entity
Add a Nginx X-Accel gestion for serve secure files
Add an ArchiveZip for download package on-the-fly
Edit the StrainImport to add the files on the chromosome and copy them in a directory

Add some informations about: best practice, coding standards, php-cs-fixer.