Transpiling of RIDE scripts to native Go code

[alexeykiselev]

Аbstract
The interpretation of RIDE scripts is slow. The idea is to transpile scripts those already in blockchain into a native Go functions and use them while importing blockchain or while validation of all scripts known at the moment of release.

Motivation and Purposes
To speedup the import and validation of blocks, to reduce the memory footprint of the node.

Specification

1. Transpiler
   Implement the transpiler as a command line utility that will extract all scripts that in given blockchain file and generate Go source code for every script.
2. Node with built-in scripts
   Include the generated functions in separate package in gowaves node. Add the index to lookup for the native function for a script. If there is a native function for a script in blockchain use it to validate transactions, if not use the default interpretation technic.

Backwards Compatibility
In case of impossibility to transpile a script the existing interpretation will be used.