BIP49/84 derivation paths and other minor improvements

This release contains bug fixes, build tool optimizations and the following new features:

• BIP49 and BIP84 derivation paths for all HD wallet related pages
• Allow import of HD master root keys in "Wallet Import helper" page

Add Wallet Import helper page

Currently, there is no easy way to import addresses from a HD seed that has been created by another software into Bitcoin Core.
This new feature helps you do that.

First release of offline version

This is the first release of the offline version of the Cryptography Toolkit.

You can find my GPG key on keybase.io/guggero, it should match the fingerprint F4FC 70F0 7310 0284 24EF C20A 8E42 5659 3F17 7720.