* Fixed accepting integer IDs in requests for Tendermint RPC server (#2366)
* added a wrapper interface `jsonrpcid` that represents both string and int IDs in JSON-RPC requests/responses + custom JSON unmarshallers
* changed client-side code in RPC that uses it
* added extra tests for integer IDs
* updated CHANGELOG_PENDING, as suggested by PR instructions
* addressed PR comments
* added table driven tests for request type marshalling/unmarshalling
* expanded handler test to check IDs
* changed pending changelog note
* changed json rpc request/response unmarshalling to use empty interfaces and type switches on ID
* some cleanup
Follow up of PR https://github.com/tendermint/tendermint/pull/724
For https://github.com/tendermint/tendermint/issues/708
Reported initially in #708, this bug was reconfirmed
by the fuzzer.
This fix ensures that:
* if the user doesn't pass in `"id"` that we send them back
a message in an error telling them to send `"id"`. Previously
we let the handler return a 200 with nothing.
* passing in nil `params` doesn't crash
* not passing in `params` doesn't crash
* passing in non-JSON parseable data to `params` doesn't crash