Fifth Beta - Massive underlying changes

Description:

This is a big release that changes lots of the underlying code for better security among many other changes. It is the first release after being released as open source.

Changelog:

• Big refraction of the gui code.
• Reworked and refactored back-end code.
  • Added multi user support.
  • Better security by dropping SHA-256 for Argon2 key derivation.
• A new login screen that works great on mobile and desktop.
• Disable share button when receiving in synchronization.
• Omit json fields that are empty.
  • Should make loading and parsing json a bit faster.
• Use regular expression checks for sync code.
• Update the regular expression checks to be much stricter.
• Improved password and username checks.
• improved error handling and printing errors to the ui.
• Rework the code for the extended entry widget.
• Add an about page with logo and release link.
• Upgrade wormhole-william to v1.0.3.
• Update the Makefile to better work with fyne-cross v2.0.0.
• Use fyne-cross v2.0.0 for building release binaries.
  • This means that binaries are built using Go 1.13.11.
  • Opens up the possibility of Android and OpenBSD releases in the future.
• Upgrade fyne to v1.3.0.
  • We are now using text wrapping where it makes sense.