6.0.0

• Feature: gzip auto detect in htaccess file (check documentation)
• Feature: Github Issue templates
• Feature: Add Cache Tags for external HTTP Cache servers
• Bugfix: Rename hook class to avoid PHP4 constructor problems
• Bugfix: Use SFC_ROOT in htaccess final rewrite rule
• Bugfix: Support links in the backend (target _blank)
• Bugfix: UnitTests incl. dev dependencies
• Bugfix: Change handling of collectGarbage and flush in BoostMode
• Task: Move DB selections to Repository functions
• Task: Rename composer scripts
• Task: Migrate static class to service class
• Task: Move guzzle related functions to seprate service class
• Task: Many code cleanups