It isn't possible to use atomic operations for floats, so don't use them there.

Having a lock is good out of other reasons too, because this way the float time
and the integer time both match, and can't get different values in a race,
e.g. when two setTimeofDay() get executed simultaneously.

Cleanup:
	* Remove volatile keyword, it is of no use at all. [1]
	* Remove the enable_if stuff. It had no use either.
	  The most likely explanation why the enable_if stuff was there is that it
	  was used as something like a STATIC_ASSERT to verify that sizeof(T) is not larger
	  than sizeof(void *). This check however is not just misplaced in a place where we
	  already use a lock, it isn't needed at all, as gcc will just generate a call to
	  to the runtime if it compiles for platforms that don't support atomic instructions.
	  The runtime will then most likely use locks.

Code style fixes:
	* Prefix name of the mutex
	* Line everything up nicely, where it makes things look nice
	* Filling \ continuations with spaces is code style rule

Added operations on the atomic var:
	* Compare and swap
	* Swap

The second point of the cleanup also fixes the Android build of the next commit.

[1]: http://stackoverflow.com/q/2484980

On Windows Release x64 bit build this changes:

ProfilerGraph::put
1.68% -> 0.061%

ProfilerGraph::draw
12% -> 17.%

So yes, there is a tradeoff between saving profiling data
(executed always) and drawing the profiler graph (executed very rarely).
But usually you don't have the profiler graph open.

Using logging for these just makes them bloated and hard to read and overally just not neat at all.

For several years now, the lua script lock has been completely broken.
This commit fixes the main issue (creation of a temporary rather than
scoped object), and fixes a subsequent deadlock issue caused by
nested script API calls by adding support for recursive mutexes.

When compiled with optimizations, the most recent versions of clang seem
to 'optimize' out a crucial "and %reg, 0x7FFFFFFF" instruction in noise2d(),
probably because it somehow assumed the variable n would never become greater
than that amount.
Indeed, signed integer underflow is undefined behavior in C and C++, so while
this optimization is "correct" in that sense, it breaks lots of existing code.
Solved by changing n to an unsigned type, making behavior well-defined.

Previously, the server called FATAL_ERROR when a Lua error occured.
This caused a (mostly useless) core dump.
The server now simply throws an exception, which is caught and printed before
exiting with a non-zero return value.
This also fixes a number of instances where errors were logged multiple times.

This allows the player to toggle continuous forward with a key (F by default),
so we don't have to hold down the forward key endlessly.

Increase default from 6 to 16 to help with mgv7 and mgfractal
Large-scale or alternative mapgens can result in a lowland spawn point not
being found, causing a spawn at (0, 0, 0) possibly buried underground
The max height is now settable to allow correct player spawn
in any mapgen or when using custom noise parameters

Use this macro to disallow copying of an object using the assignment
operator or copy constructor.  This catches otherwise silent-but-deadly
mistakes such as "ServerMap map = env->getMap();" at compile time.

If so desired, it is still possible to copy a class, but it now requires
an explicit call to memcpy or std::copy.

-> Put access to time variables under the time lock.
-> Merge both time locks, there is no point to have two locks.
-> Fix the lock being released too early in Environment::setTimeOfDay
-> Add serverside getter so that you don't have to get
	the environment if you only have the server

Also fix a potential seed truncation issue on platforms where the
range of ptrdiff_t (the underlying type of lua_Integer) is too small.

abort() doesn't benefit from the high level abstractions from FATAL_ERROR.

Remove outdated loglevel list from a l_util.cpp comment,
and rather point to the updated code.

Fixes #3280

- Disabled by default (except players)
- Fixes #2984

Previously, the invocation of Logger::addOutput(ILogOutput *out) led to
an out of bounds write of the m_outputs vector, resulting in the
m_silenced_levels array being modified.

Fortunately, the only caller of that method was android system logging,
and only since a few commits ago.

Complete set of parameters for each of mandelbrot and julia sets
The julia set structure often needs different iterations and scale