ETE 4.0

• Full Python 3 support (and dropping 2.7 compatibility)
• Improved installation, releasing systems and packaging
• Official Windows support? (power shell should be easy)
• Fix all reported bug and bug-minor issues
• New features:
  • New module for side-by-side tree comparison: tree-diff
  • TreeMatcher module (regular expression tree-based searches)
  • Interactive large tree visualization (smartview module)
  • GTDB taxonomy module