Separate rockspecs for each backend.

[moteus]

This allows install only needed modules without additional deps.

[lipp]

this is a very clean approach. i am hesitating though since this will releases and versioning more complicate i guess. maybe we can add some tag/release script to this PR?

[moteus]

maybe we can add some tag/release script to this PR?

You mean generate rockspecs?
I work on Windows so I think I can use only Lua (not bash)
Maybe somewhere there is such a tool.

[moteus]

I found that websocket.tools uses mime module from luasocket.
So I have two options

1. Add luasocket in dependencies to websocket.core
2. Use some base64 module. And check at load time which one to use (base64, basexx, luasocket).
   In this case I suggest add basexx module as dependency because it pure Lua module.

[lipp]

@ntd introduced using luasocket mime here:
40a02ae

lluv changes the premises as every other (minimal) impl always required luasocket.

i'd like to re-add the base64 variant from:

lua-websockets/src/websocket/tools.lua

Line 111 in 8c70f5e

local base64chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'

so dependencies are not going wild.