Closes #265

Escape command block commands for formspec

Disabling LuaJIT for user code enables normal working of debug.sethook() even for loops. The drawback is that that code will run more slowly.

The fourth parameter of string.find indicates whether the second parameter should be interpreted literally (true) or as a pattern (false). Allowing patterns enables DoS attacks, but it's possible to
allow literal matching with little effort, by disallowing the function only if the fourth parameter (plain mode) is not `true`.

fixes #255

prohibited, remove pcall and xpcall, fix global lookup of "jit"
variable, correct error locations

Thanks to @ShadowNinja and @gamemanj for fixing this in #241

Please use the screwdriver if you want to rotate trapdoors.
This reverts commit 417a136c.

and remove debug output

This is a major speedup for large mesecon machines / structures.
Force-loaded areas are stored in a file to be persistent over server
reboots. By default, areas are unloaded after 10 minutes (600s) without
usage, this can be customized with the mesecon.forceload_timeout
setting. Please turn max_forceloaded_blocks up for better performance.

Call mesecon.on_dignode / mesecon.on_placenode to take care of that.

up/down pistons from certain directions

Merge branch 'playerdetector_update' of https://github.com/HybridDog/minetest-mod-mesecons into HybridDog-playerdetector_update

Merge branch 'fix_pistons' of https://github.com/HybridDog/minetest-mod-mesecons into HybridDog-fix_pistons

I've implemented a new door API in minetest_game that
performs all the needed things to assure doors are
properly openend and closed, without mods needing to
know the inner details of what needs to be done.

Mesecons can just fetch a reference to the door object
and call the appropriate open or close method, which
simplifies this code a lot.

For compatibility, this code retains the old code path
and tests whether the new API is available, so this
code remains functional if the new API is not available.

Since the metal trapdoor was only recently added, I added
it to the new API codepath only, it's unlikely to be
present on older versions of minetest_game anyway.

As a benefit from the new door API, there is now
absolutely no more accidental switching closed trapdoors
to open on power off, which could happen with the
old method - since that was just a simple toggle.

Playing stereo sounds positionally in OpenAL causes it to play
the sounds unattenuated - same volume for all distances. This
shouldn't happen, and makes noteblocks unneccesarily loud from
very far away.

Convert all noteblock samples to mono, 22kHz 64kbit.

Major change: Documentation is now included with mesecons, the website just extracts the documentation in a more readable format

This makes development of new features easier, as documentation can automatically be updated on the website without modifying the website's code!
Every mod that has nodes in the mesecons modpack has a "doc" folder that contains subfolders with recipe, description and preview of the block. The website will discover which documentation is available
by reading the documentation.json file.

If size limit is exceeded, the luacontroller overheats. Overheating will cause the memory
to be erased.

This caused #238, reverting that commit fixes #238.

This reverts commit 30468b09.

Use right mouse button instead of left to press button and change state of switch and lever.