Escrow Mecenas

Changes include:

• total internal restructure,
• contract versioning,
• three new versions of Mecenas contract
  • version 1.1
    Improved portability, standardized completion, fixed problem with receiving the last payment
  • version 2
    The same as 1.1 + receiver additional protection - contract can't be terminated unless the receiver is inactive for a month
  • version 3.
    The same as 1.1 + receiver additional protection - additional escrow (just add an arbiter address).
    (compatible only with the unreleased, github version of EC at the moment)
• contract management more intuitive
  - execute the contract on button click instead of transaction preview,
  - better support of atomized contracts - total value, total recurring value in UI
• Improvement in terms of UX
  - enter number of repetitions instead of total value in contract creator,
  - monospace fonts for addresses, contracts sorted by role.
  - Receiving to an imported address wallet ( creating contracts in such wallets still not working)