This avoids silly mistakes when calling radians(180) instead of
radians(180.0). The first one used to return 3 instead of 3.14159…

We already have the convenient degrees() and radians() functions to convert
between angle formats. This commit involves a lot of refactoring here and
there and I may have missed some places where conversions were needed. But
hopefully there aren’t may such places.

The name “re” came from “reciprocal” but since we have “inverse” for
matrices, I thought it would be nice to make everything consistent.

This is to avoid confusion with Scene::AddTile().

The old public API is maintained for now but should be considered
deprecated.

This lets us use the code for non-float variable types. I also got
rid of the mat4-to-quat code so that users are forced to use the
mat3-to-quat code and possibly discover places where their code is
suboptimal.

- removed 0 CR characters
 - removed 12 trailing whitespaces
 - replaced 0 tabs with spaces
 - fixed 15 svn:eol-style properties

Merge threadbase.h into thread.h since we no longer need to have “secret”
thread implementations; all the platforms we care about have std::thread
or just don’t support threads at all.

Since C++11 threads are available on every platform that has threads, we
no longer need our pthread implementation. The LOL_FEATURE_CXX11_THREADS
macro is gone, too, and we now just use LOL_FEATURE_THREADS.

Note that it is still necessary to link with -lpthread or -pthread on
some platforms, so we don’t throw that part away.

Add mingw-std-threads project to external/ for full C++11 thread support, fix
an incorrect Win32 fix I did in PEGTL, work around mingw’s <io.h> declaring a
conflicting eof symbol, and fix a capitalisation error in log.cpp.

The C++ standard (21.5 Numeric conversions) says that %lld must be available,
however mingw still does not support it and in the meantime the most practical
solution seems to use long int instead of long long int.

It merely performs an std::swap() on both array elements, but it’s
apparently convenient to have.