v6.4.0: Progress toward macOS App Store packaging

Attempted to reduce the display complexity somewhat; still requires a lot of focus.

I believe that the signatures on the .pkg and the .app.zip should allow installation without
issue, but still not adequate for macOS App Store inclusion.

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The SLIP39.app won't allow you to browse and change directory; use:

python3 -m pip install slip39

instead, and then run:

slip39-gui

v6.2.0: SLIP39.app macOS app signing valid

The macOS SLIP39.app is now correctly signed, and should unzip and run without complaint.

v6.1.0: Improve formatting, colors

Minor release with formatting, color improvements.

Also allow selection of card sizes in GUI.

v6.0.0: Better passphrase handling

While SLIP39 allows encryption of seeds using a passphrase, Trezor does not
use this feature. Therefore, warnings have been added to the GUI to this effect.

The GUI has also been improved for visual flow and sizing.

v5.3.0: Create and Verify Seed Entropy

Managing Entropy during wallet seed creation is one of the weakest
points of most Cryptocurrency wallet creation applications.

How do you know that the Entropy of really good? Or, that it hasn't been
interfered with, in order to steal your wallets?

All Entropy used during seed creation and derivation is now completely visible.

The resultant SLIP-39 Mnemonics are also tested, to ensure that the original
seed data is recoverable using the Mnemonics.

v5.2.0: Initial macOS App Release

Creating Ethereum, Bitcoin and other accounts is complex and fraught
with potential for loss of funds.

A BIP-39 seed recovery phrase helps, but a single lapse in security
dooms the account (and all derived accounts, in fact). If someone finds
your recovery phrase (or you lose it), the accounts derived from that
seed are /gone/.

The SLIP-39 standard allows you to split the seed between 1, 2, or more
groups of several mnemonic recovery phrases. This is better, but
creating such accounts is difficult; presently, only the Trezor supports
these, and they can only be created "manually". Writing down 5 or more
sets of 20 words is difficult, error-prone and time consuming.

The [python-slip39] project exists to assist in the safe creation and
documentation of [Ethereum HD Wallet] seeds and derived accounts, with
various SLIP-39 sharing parameters. It generates the new random wallet
seed, and generates the expected standard Ethereum account(s) (at
derivation path m/44'/60'/0'/0/0' by default) and Bitcoin accounts
(at derivation path m/84'/0'/0'/0/0' by default), with wallet address
and QR code (compatible with Trezor derivations). It produces the
required SLIP-39 phrases, and outputs a single PDF containing all the
required printable cards to document the seed (and the specified derived
accounts).

On an secure (ideally air-gapped) computer, new seeds can safely be
generated and the PDF saved to a USB drive for printing (or directly
printed without the file being saved to disk.). Presently, `slip39' can
output example ETH, BTC, LTC and DOGE addresses derived from the seed,
to illustrate what accounts are associated with the backed-up seed.
Recovery of the seed to a Trezor is simple, by entering the mnemonics
right on the device.

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The SLIP39.app is signed by Perry Kundert, but the signature is not yet recognized
as a known App Developer. Therefore, you will have to approve the app in System Preferences /
Security & Privacy / Privacy.