This implies creating a trimmed down branch that contains almost
nothing. It will then be usable by projects that do not need the
complex build system, and by the engine itself as a submodule from
the same repository.

Using “Array” instead of “array” is now fully deprecated, and I replaced
the Log::Debug() etc. functions with msg::debug() etc. because log:: was
unavailable due to being a maths function.

Added up-to-date copyright notice and BOM to modified files, just in case.

The containers no longer force the user to use the ptrdiff_t type for
size information. For convenience, size() now always returns an int,
and the size_s() method offers a way to handle arrays with more than
2 billion elements. Internally, we still use ptrdiff_t, though.

Since so much code had to be changed, I took the opportunity to get
rid of capitalised accessors for classes that are lowercase.

MASK to SWIZZLE in the vector templates, rename matrix<> to mat<> for
consistency, implement transposition for all matrix sizes, make matrix
columns private and only accessible through operator[].

quaternion, improve quat::rotate(vec3, vec3) to gracefully handle corner
cases, and add unit tests for all of these.

Camera & vector.cpp : Fixed shifted_perspective crash with almost zero FOV.

numeric : Added SmoothClamp & swap
camera : fixed target&up issues and added screen-scale factor.
touky_demo : correct camera integration & first pass on uro refactor. Also added Makefile to vcproj

MeshViewer : Camera update and small object tweak.
             ortho to perspective transition is now perfect.

to get M_PI from the platform headers and cast it to float.

compilation time for very little benefit and maybe even confusion.

functions; also remove a lot of idiotic "using namespace std" from the
codebase.