Rewrite configuration

[Avimitin]

Here are some problem the current configuration have:

• The load sequence of plugins and their corresponding configuration are mixed together, which causing bug like #57
• The colorscheme lazy loading required too much if condition code base
• Separate plugins source and plugins configuration may not be a good idea, cuz currently, it is hard to find configuration for a plugin, or find the configuration related plugin.
• Use a default configuration, then inject a custom.lua file to change it, this is not neovim way to do the config stuff

[Avimitin]

Request for Comments

Here are some of solutions.

• New directories layout

  init.lua
  lua/
      - editor/
      - plugcfg/
      - *.repos.lua

• Machine local and editor options merge into vim.g.nvcfg.
• All the huge configuration split into plugcfg/<name>.rc.lua