Development version 8.1 is ready

This is the first development release of the 9.0 version. The main feature of the version are updates to the game's UI: better numerical fields, more colors in the knowledge screen. Also, it brings fixes for many bugs. Binaries are available for Linux and Windows (both 64-bit). Below, you can find major changes since the last major release:

Added

• Ability to clear numeric fields (GitHub issue #95)
• Numeric fields to sliders (GitHub issue #96)
• Block the player from moving in-game dialogs outside the game window
• The separated color on the list of known bases for the base which is set
  as target for the player ship
• The separated color on the list of known events for the event which is set
  as target for the player ship
• The separated color on the list of accepted missions for the mission which
  is set as target for the player ship

Changed

• Updated README.md
• Updated look of the crew members info's dialog, lists of the known bases and
  events

Fixed

• No check for the correct amount of items to craft during setting a crafting
  recipe
• Set proper max amount of money to train when the player doesn't have enough
  money for training
• Crash when moving around in-game dialogs with mouse (GitHub issue #98)
• Cursor position inside some numeric fields after entered a number
• Loading weapons into the game
• Setting the list of available items' types during trading, looting bases and
  in the player's ship's cargo
• Keyboard shortcuts for setting the player's ship's speed
• Showing the destroyed ships in the game statistics
• Crash on finished boarding combat
• Crash on entering the game statistics when there is a list of killed mobs
• Starting ship for the Inquisition faction and Hunter career
• Reading factions' flags from files
• Faction with fanaticism flag should start the game with maxed morale