New PascalCoin Build 2.0

Source code at GitHub:
https://github.com/PascalCoin/PascalCoin

Download windows installer and Linux binaries at SourceForge:
https://sourceforge.net/projects/pascalcoin/files/

### Build 2.0.0.0 - 2017-06-23
- MANDATORY UPGRADE - HARD FORK ACTIVATION WILL OCCUR ON BLOCK 115000
- Introducing Protocol v2.
  - https://github.com/PascalCoin/PascalCoin/blob/master/PascalCoinWhitePaperV2.pdf
  - Core Changes:
    - New safebox hash calculation algorithm to allow safebox checkpointing
    - Improved difficulty target calculation to obtain a more stable average blocktime of 5 minutes, given abrupt hashpower fluctuations
    - Bug-fix for China region users
    - Anti-spam measures
      - New Consensus Rule: A block can only contain 1 zero fee operation per sender account. If a sender account issues 2 or more zero-fee operations, that block is invalid.
    - SafeBox now stored in chunks to facilitate checkpoint distribution
   - Reintroduce orphan blocks operations on main blockchain 
  - Added Checkpointing:
    - Checkpoint created on every 100'th block
    - Added network operations to transfer Checkpoint chunks (compressed)
  - Addded In-Protocol PASA Exchanging:
    - New Operation: List Account, used to list an account for public or private sale
    - New Operation: Delist Account, used to delist an account from sale
    - New Operation: Buy Account, used to purchase an account lised for sale
    - Updated Operation: Transaction, can be used in place of Buy Account operation in private account sales
  - RPC API Changes:
    - All changes are backwards-compatible for current 3rd-party infrastructure providers (exchanges, wallets).
    - However, use of param "ophash" has been changed in V2, see "Operation Object changes" section to know how to use "old_ophash" param value   
    - JSON changes:  (see at github)
  - GUI changes:  (not available on daemon)
    - New columns "name" and "type" on accounts
   - Information about Accounts/Operation using F1
    - Operations form now accepts:  (Will be active after V2 protocol activation)
      - List account for sale (public or private)
      - Delist account
      - Buy account
     - Change account name/type
    - Operations form allows to search for accounts using F2 over an account edit box
    - Changes in text showing operations information
- Other changes:
  - Bug for china users fixed 
  - Bugs fixed