* Fix leak like behaviour if you load multiple schematics in a loop.
* Cleanup check in for, fixing theoretical out of bounds read if
Schematic::deserializeFromMts reduced the number of elements
in m_nodenames. A != check may need an overflow of the counter
before it hits, if origsize is larger than m_nodenames.size().
* Fix function name passed to errorstream: it was wrong. Also use
__FUNCTION__ instead of manually using the method name at other
places in the function.
* Don't shadow the name member in the loop.
This fixes #3935, a regression from 0338c2e.
An 'optimization' was performed where an index for the VoxelManip being
operated on was mistakenly used for bounds checking within the incorrect
VoxelArea, namely, the area wherein light should be spread.
2016-03-27 15:47:01: ERROR[Main]: ServerError: Lua: Runtime error from mod '*builtin*' in callback luaentity_Step(): Node name is not set or is not a string!
2016-03-27 15:47:01: ERROR[Main]: stack traceback:
2016-03-27 15:47:01: ERROR[Main]: [C]: in function 'add_node'
2016-03-27 15:47:01: ERROR[Main]: /usr/share/minetest/builtin/game/falling.lua:96: in function </usr/share/minetest/builtin/game/falling.lua:43>
Commit
65c09a96f4 "Set acceleration only once in falling node"
has made the acceleration being set only once.
But this has introduced a regression.
Fix #3884.
Undoubtably this may cause problems later if unchecked.
```
2016-03-22 21:57:52: WARNING[Server]: Assignment to undeclared global "options" inside a function at .../sofar/git/minetest/bin/../builtin/game/chatcommands.lua:862.
```
This allows the player to more easily target and punch connected
nodeboxes, especially if they have a fixed nodebox that is very
small, like technic cabling, or xpanes. Tried it on fences and
my xpane conversion, and happy with the result.
Changes:
* Fix indentation.
* Pass strings by const reference.
* Merge Strfnd and WStrfnd into one class instead of copying them.
* Remove trailing spaces.
* Fix variable names.
* Move to util.
* Other miscellaneous style fixes.
