Revert "Use "we-" prefix for commands"

This is currently being discussed, see #62.
This reverts commit 1024eace6f342a340ef84583b2c0c97d657ad326.
Fix bug with loading old .we file formats, thanks to @Sokomine
Fix stack2 param
Fix stack2 amount count
Fix stack2 sign recognition for y & z
Merge pull request #68 from KodexKy/stack2_fix

Fix stack2 param
Fix some warnings.
Fix crash when loading schematic in a LuaJIT build in recent Minetest versions (thanks LazyJ & VanessaE!).
Cleanup and fixup

Non-stylistic changes:
  * Add LuaDoc/LDoc support.
  * Fix `clear_objects` area size calculation.
  * Fix `clear_objects` removing player objects.
  * Fix shadowing of marker entity name with player name.
  * Make visualization functions use `swap_node`.
  * Make hidden nodes unwalkable.
  * Prevent `hide` from hiding air.
  * Make deprecated functions log to deprecated stream when called.
  * Fixed `we-replaceinverse` not using normalized node names.
  * Added .gitignore.
  * Bump version to 1.1.

Stylistic changes:
  * Change `x = function` to `function x`.
  * Change comment format.
  * Make  missing VoxelManip error less obnoxious.
  * Move `sort_pos` into `common.lua`, which is a required module.
  * Remove local copies of `minetest`.
  * Remove `worldedit = worldedit or {}` from modules.
  * Replace replaceinverse with an inverse argument to `replace`.
  * Added `error()`s on on invalid axes.
  * Change `wip` to `TODO`.
  * Rename `clearobjects` to `clear_objects`.
  * Remove `hollow_{sphere,dome,cylinder}` and replace them with a hollow parameter to each function.
  * Add helpers to reduce code duplication.
  * Renamed `Chat Commands.md` to `ChatCommands.md`.