[ZcF-general] ZecWallet June update

[adityapk]

This month, ZecWallet made notable progress in two areas:

- Fast Sync
  - ZecWallet now has "fast sync" support for new wallets that syncs the Zcash blockchain ~33% faster. It does so by doing PoW and other checks for blocks behind a checkpoint, skipping the most expensive Tx checks (Since the user doesn't have a wallet yet)
 - Fast sync is available in the embedded zcashd in ZecWallet

- ZecPaperWallet
 - Thanks to a generous grant from the Zcash Foundation, we shipped a offline paper wallet for Shielded (and transparent) addresses.
  - Support for several platforms, including ARMv7, ARMv8, MacOS, Windows, Linux, TailsOS and more.
  - A user friendly UI frontend to generate and save the paper wallets
  - Save to PDFs or Text files

- A vanity address generator for sapling addresses that can generate a sapling address with a chosen prefix.