[Meta DEx] enable RPC calls, add missing "cancel" logic

[dexX7]

Part I)

The meta DEx RPC calls are currently completely "removed" via preprocessor makros, however, this is only user faced, and does not affect how meta DEx transactions are parsed, so there should basically be no difference. Using the category "hidden" further hides the calls from help, but they can be used nevertheless. This seems handy for testnet or regtests.

Part II)

This implements the missing logic of "cancel" operations on the meta DEx.

To quote the spec, in particular for action = 4:

An offer to sell coins can be changed or cancelled by publishing additional transactions with metadex sell offer sub-action variations:

• Action = 1 (ADD) orders are merged (both in the database and the UI) when their unit prices are exactly the same.
• Action = 2 (CANCEL-AT-PRICE) cancells open orders for a given set of currencies at a given price. It is required that the currency identifiers and price exactly match the order to be canceled.
• Action = 3 (CANCEL-ALL-FOR-CURRENCY-PAIR) cancels all open orders for a given set of two currencies (one side of the order book).
• Action = 4 (CANCEL-EVERYTHING) can be used to cancel all open orders for all currencies within one ecosystem, if currency identifier for sale and currency identifier desired are within the same ecosystem, otherwise all open orders for all currencies of both ecosystems are cancelled.

When using action = 3 (CANCEL-ALL-FOR-CURRENCY-PAIR) the validity of the following fields is not tested:

• Amount for sale
• Amount desired

When using action = 4 (CANCEL-EVERYTHING) the validity of the following fields is not tested:

• Currency identifier for sale
• Amount for sale
• Currency identifier desired
• Amount desired

[m21]

Guys check out my old branch for 10:mastercoin-MSC@61f808a
I simply reenabled Metadex , but more importantly renamed all the binaries to "omnicore" in previous commits.

[dexX7]

Let's give this a few more days, but at least one "it's good to go" would be great.

As next step, I'd split mastercore_dex into mastercore_dex and mastercore_mdex, because both have basically nothing in common, and come with a very different logic.

[zathras-crypto]

I checked this out when you first put it out mate, "it's good to go" WRT the RPC stuff. The cancel stuff though I can't comment on until I dive into MetaDEx math/logic, which I've been purposely avoiding while I catch up on the rest of my work queue.

This implements the missing logic of "cancel" operations on the meta DEx.

I wondered about this part - so @m21's implementation as it stands has no cancel operations or broken cancel operations?

[dexX7]

Alright, in this case it might make sense to split the PR, since it seems there might be time for further discussion.

The more obvious part: the checks for CANCEL_AT_PRICE and CANCEL_ALL_FOR_PAIR are indeed missing and tagged as TODO. The PR just fills the blanks here.

The missing logic of CANCEL_EVERYTHING goes a long way back from mastercoin-MSC#219 to OmniLayer/spec#292. Initially, this command canelled all offers of both ecosystems in any case, and it's behavior was changed to:

Action = 4 (CANCEL-EVERYTHING) can be used to cancel all open orders for all currencies within one ecosystem, if currency identifier for sale and currency identifier desired are within the same ecosystem, otherwise all open orders for all currencies of both ecosystems are cancelled.

This was something undefined, spec wise, at that point, and neither covered by the test plan.

[dexX7]

The last commit is a fix for minimal faulty code as well as a undefined variable and a straight forward optimization of the initialization of those variables.

I'm going to start testing of the merged version now, and if there is flawless, which I expect, given the intensive testing some weeks ago, as well as when I submitted this PR, this is good to go.

For once, because any further work on the meta DEx is dependant on this PR, and it further looks like @zathras-crypto is already integrating the meta DEx UI into #5.

Regarding the logic: this was specified more than a few weeks ago, and this PR merley catches up with the spec. If, for some reason, the spec gets changed again, it can be addressed by a follow up PR.

[dexX7]

Travis CI build result: passed
https://travis-ci.org/dexX7/bitcoin/builds/57771300

RPC tests via bitcoin-spock: passed
http://bitwatch.co/uploads/omnicore-pr-8/

RPC tests via mastercore-rpc-tests, including meta DEx test plan: passed
http://bitwatch.co/uploads/omnicore-pr-8/run_future_tests.log

Test summary:

ExodusPurchaseTest ... successful
SimpleSendTest ... successful
PropertyCreationTest ... successful
P2SHTest ... successful
TraditionalDexTest ... successful
SendToOwnersTest ... successful
MetaDexPlanTest ... successful
MetaDexCancelAtPriceTest ... successful
MetaDexCancelPairAndLookupTest ... successful
DexCrossEcosystemSideEffectsTest ... successful
MetaDexCancelEverythingInSameEcosystemTest ... successful
MetaDexCancelEverythingIgnorePropertyTest ... successful
MetaDexCancelEverythingScopeTest ... successful

13 of 13 tests successful (0 skipped)