Cleanup and fixup

[ShadowNinja]

Non-stylistic changes:

• Add LuaDoc/LDoc support. Generate API documentation with ldoc .. (see screenshots below)
• Fix clear_objects area size calculation.
• Fix clear_objects removing player objects.
• Fix shadowing of marker entity name with player name. (this broke clear_objects in yet another way)
• 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 (Just *~ for now).
• Bump version to 1.1.

Stylistic changes:

• Change x = function to function x.
• Change comment format. ("--foo" -> "-- Foo")
• Make missing VoxelManip error less obnoxious.
• Move sort_pos into common.lua, which is a required module (it was already copied about three times, and it needed to be copied again for a module that was missing it, there's not really a reason to exclude it too, so requiring it is O.K.).
• Remove local copies of minetest. (Anything that used a core function in a speed-critical area localized the specific function needed, so the speedup was minimal)
• Remove worldedit = worldedit or {} from modules. (init.lua defines this)
• 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 (LDoc has an issue with the space).

Generated documentation (this is a little outdated, but it's mostly the same): Note: Due to the number of changes it's hard to thoroughly test this, so I wouldn't be surprised if this introduces a few bugs.

[ShadowNinja]

Bump.

[ShadowNinja]

Bump. @Uberi & @sfan5

[Uberi]

We'll need to rebase this, of course, but the changes look really good overall! Is it possible to include an HTML copy of the LuaDoc output with the downloads, so users don't have to install it?

[ShadowNinja]

@Uberi Of course, but not with GitHub's auto-archives (or at least, not without polluting the commit history with doc re-builds and including a built version in the repo). You'll have to make custom archives. GitHub will host them for you if you make a release though. You can set up a Travis script that auto-updates the docs in a GitHub pages repo too. Of course, you can also host the docs on your own site (with a script to auto-update them, probably fairly trivially implementable in Python with GitHub's commit hook system, a builtin simple HTTP server library, and the subprocess library) and link to them.

[ShadowNinja]

Rebased.

[ShadowNinja]

@Uberi So... good to merge now?

[Uberi]

Oh, for sure - everything looks good to me. In the future, feel free to merge changes after code review!