small misc syntactic fixes

small misc syntactic fixes

add cumulative chain work to 'getchaintips'

f7d958d Free the DEx and allow other tokens to be traded (dexX7)
1e7bd04 Ensure there can only be one active offer, when creating a new DEx offer (dexX7)
7e34e10 Handle DEx payment based on offer for sale (dexX7)
dceb321 Only check for primary tokens, when DEx is not free yet (dexX7)
eeaa883 When creating DEx orders, parse amount based on token divisibility (dexX7)
f57de0e When creating DEx offer, check there is no other (dexX7)
158250d Add feature activation for freeing the DEx (dexX7)

Pull request description:

  This pull request updates the traditional distributed exchange, where users can trade Omni and Test Omni for Bitcoin.

  When this feature is activated, any token can be traded and it's no longer limited to the two primary native tokens of the Omni Layer protocol.

Tree-SHA512: ea7836279463e9e399ee3a054ee537badc4701d85d30cbd9a0f2608c533e5cd82b07ac8d04fb2cf644cd5d4add60927b4de236e232795104b8e03581363cd50f

c2f9f79 [Doc] Add GUI addressbooks sorting in the release notes (random-zebra)
5436a07 [GUI] Add sorting controls and connect them in addresseswidget (random-zebra)
77a8440 [GUI] Connect sort controls in coldstaking and receive widget (random-zebra)
51edff8 [GUI] Add controls to sort addresses in receive/coldstaking widget (random-zebra)
da23ce2 [GUI] Sort MyAddresses/Contacts/ColdStakingAddresses by label (random-zebra)

Pull request description:

  This adds GUI controls and relative logic to sort the addresses saved in the wallet and presented to the user.
  Interested views:
  - Receive --> My Addresses
  - Cold Staking --> My Cold Staking Addresses
  - Contacts
  - Send / Delegate --> recipient dropdown

  Addresses can now be sorted (ascending or descending order):
  - by label (default)
  - by address
  - by creation date.

  Closes bitcoin#1038 .

  ---

  For "receive" addresses and own "cold-staking" addresses, the controls are hidden with the list, and show up when the relative button is pressed:
  <br>

  ![sort_addys_1b](https://user-images.githubusercontent.com/18186894/76258309-992ea500-6253-11ea-974a-9b759a020a83.gif)

  ---

  <br>
  For "contacts" the controls are visible next to the title
  <br>

  ![sort_addys_2](https://user-images.githubusercontent.com/18186894/76258332-a3e93a00-6253-11ea-896b-745e21a71873.gif)

  ---

  <br>
  For the dropdown in the "send" widget, instead, a fixed by-label ascending order is used (adding controls for customization here would be probably useless and only make the the space overcrowded).
  <br>

  ![sort_addys_3](https://user-images.githubusercontent.com/18186894/76258372-b3688300-6253-11ea-9483-0ff175378fb3.gif)

  ---
  <br>

  Note: currently based on top of:
  - [x] bitcoin#1385

  The present diff starts with the second commit.

ACKs for top commit:
  furszy:
    ACK c2f9f79 .

Tree-SHA512: 7788b6d7eb7e1a966d2e1f0c0de95691d217571f440de1ec75732d7fd23a8251ea4cfbe37163d650bd2eb591ad8115affb1843c62253fe501540a34b93e91d86