Generic predicate's framework

[MastaP]

the top level predicate (locking script) data structure is a triple <id, code, params> where id is uint to identify the runtime, code and params are byte arrays allowing to encode the necessary logic

[MastaP]

#16

[martti007]

Whole predicate structure was rebuilt. When predicate is parsed, it is left as encoded predicate strucuture. When transaction needs to be verified it is parsed by specific predicate engine and predicate is verified. Also encoding now assumes that all predicates have serialization methods to serialize predicate with the token whenever nessessary

[b3y0urs3lf]

This task was tested within tasks

1. GetInclusionProof must return UC for non-inclusion proof aggregator-go#55 (comment)
2. Unicity certificate parsing #11 (comment)
   Also recently I tested redis task Cleanup the queue of incoming commitments after processing aggregator-go#50 where I executed and amended cucumber tests, which now use mentioned above rebuilt predicate structure.

Moving task to done.