Version 4.0.0beta1

*/!\ This is a beta version /!*

• Make the UI compatible with remote-mode setup (Julien Rouhaud)
• Query and display powa-collector information (Julien Rouhaud)
• Expose system cache hit / disk read metrics on global and per-database
  pages (Julien Rouhaud)
• Expose new metrics added in pg_stat_kcache 2.1 (page faults, context
  switches...) on global, per-database and per-query pages (Julien Rouhaud)
• Add wait events graphs on global and per-database pages (Julien Rouhaud)
• Add queries per second counter on global and per-database pages (Julien
  Rouhaud)
• Display configuration changes and PostgreSQL restart on graphs when
  pg_track_settings is configured (Julien Rouhaud)
• Fix longstanding bug in graph hover boxes position (Julien Rouhaud)
• Provide metric definitions and link to the documentation on the graph
  (Julien Rouhaud)
• Fix the graph preview selection (Julien Rouhaud)
• Add pg_wait_sampling in the config extension list (Julien Rouhaud, thanks
  to Adrien Nayrat for the report)
• Don't try to detect if a hypotetical index would be used if no suitable
  index is detected (Julien Rouhaud, thanks to Guillaume Lelarge for the
  report)
• Fix lost filter when changing the time range (Pierre Giraud, thanks to Marc
  Cousin for the report)
• Fix database wizard query validation for pg11+ (Julien Rouhaud)
• Handle hypopg unsupported access methods in dataabase wizard (Julien
  Rouhaud, thanks to Adrien Di Mascio for the report)
• Fix compatibility with SQLAlchemy 1.3+ (Julien Rouhaud, thanks to github
  user mchubby and irc user ChOcO-Bn for the report)
• Fix query detail if no data is found on the selected range (Julien Rouhaud,
  thanks to irc user ChOcO-Bn for the report)
• Fix some metrics in wait events and general query datasources (Julien
  Rouhaud, thanks to Adrien Nayrat for the report)