Nuova versione

# Release 2.6
 * The source code is relicensed under the MIT Licence
 * First official release of the Kivy GUI, with android APK
 * The old 'android' and 'gtk' GUIs are deprecated
 * Separation between plugins and GUIs
 * The command line uses jsonrpc to communicate with the daemon
 * New command: 'notify

'
 * Alternative coin selection policy, designed to help preserve user
   privacy. Enable it by setting the Coin Selection preference to
   Privacy.
 * The install wizard has been rewritten and improved
 * Support minikeys as used in Casascius coins for private key import
   and sweeping
 * Much improved support for TREZOR and KeepKey devices:
   - full device information display
   - initialize a new or wiped device in 4 ways:
     1) device generates a new wallet
     2) you enter a seed
     3) you enter a BIP39 mnemonic to generate the seed
     4) you enter a master private key
   - KeepKey secure seed recovery (KeepKey only)
   - change / set / disable PIN
   - set homescreen (TREZOR only)
   - set a session timeout.  Once a session has timed out, further use
     of the device requires your PIN and passhphrase to be re-entered
   - enable / disable passphrases
   - device wipe
   - multiple device support