Store cat code within external lua file

[ZackeryRSmith]

Cat's are currently pretty hard coded which I'd really like to avoid. Having to compile the whole project (which also means installing quite a few things) shouldn't be required. Especially if you only want to tweak a small thing with how the cat operates.

Why Lua?
There is various reason why I choose Lua to provide the scripting support:

• Its low footprint and superior speed as compared to other scripting frameworks.
• In version 2.0, Lua had a major restructuring which had led toward significant performance gains.
• Lua has a JIT compiler, which is very fast (with a very small footprint).
• When compared to other popular scripting platforms such as Python, Lua uses a much smaller memory footprint.
• Lua has a simple, but very efficient, syntax.
• It has out-of-box support for passing anonymous functions as arguments, map/array as one concept called “table”, meta functions, and meta tables, allowing implementation of various programming paradigms.
• Lua provides a very low-level C API

I plan on using the LuaCpp library to integrate Lua in this project. As using the Lua low-level C API would require me to learn the internals of the Lua engine before I could even imagine using it in bongocat-plus. LuaCpp addresses this issue; it's a lightweight wrapper for Lua C APIs that provides access to the Lua library.

[ZackeryRSmith]

See the refactor branch, and for active dev-logs join the Discord go to #dev-logs and click Bongocat-Plus

[ZackeryRSmith]

This issue has been reopened to keep as a tracker. Although Lua scripting now has an API and is technically supported. Many things need to be ironed out. To keep this tracker simple, I will close this issue once Bongocat-Plus can do the following:

• Load Lua scripts from the cat directory
• Load cat by name in config.json