iPad redesign and other improvements

In this version, we redesigned the iPad main screen. Also, we improved the address book entity editor. Furthermore, we added the colour setting for the dark mode, so you can now choose a colour for the light and dark mode. Finally, we fixed the message view eliminating horizontal scrolling.

The complete list of changes is here:

• Redesigned the iPad main screen
• Redesigned the address book editor
• Added separate colour settings for light and dark modes
• Fixed the message view screen
• Fixed previously broken selection mark in the message list edit mode
• Added a currently showing message selection to stay visible on iPad
• Revised code for the depreciation/warnings
• Added a FAQ page
• Other minor improvements and bug fixes