Reduced server CPU usage on NodeMetadata step()s. Also furnace now cooks while no players are near it.

Updated licenses of CiaranG's contributions to be in line with the new contribution policy and added a TODO note to server.cpp

...and added support for simple time usage profiling in the last one.

--HG--
extra : rebase_source : 9826d20176134a53ff232816a10407465d8c0f50

--HG--
extra : rebase_source : bb7c083b9ab2989d90f41255b85e9e3edaf578ef

--HG--
extra : rebase_source : 8ad4d13fc7ab1088ebd18cf968d912949aab8eae

--HG--
extra : rebase_source : 2695ad71185244cefbcf6e3e28ba1ab5e54c882f

--HG--
extra : rebase_source : 7260636295d9068fbeeddf4143c89f2b8a91446c

a work-in-progress map modified callback interface (committing because i want to merge the fence stuff)

Added a check that avoids server crash (unhandled exception) when map generation is attempted near limit

--HG--
extra : rebase_source : e8ec407f60711d42d33be4811b2880088f617b5b

mud placed in sunlight no longer instantly turns to grass; also tuned transforming speed a bit (will be made a lot longer when testing is complete)

Moved the temporary mapgen test files and added a modified map.cpp too... These are probably useful in the next mapgen update and shouldn't be lost.

--HG--
rename : src/noise.cpp.new => misc/noise.cpp
rename : src/noise.h.new => misc/noise.h

Add (possibly non-compatible) work-in-progress noise.{h,cpp} so that they won't be accidentally lost. These are useful for upcoming mapgen updates.