Fixed old references to Buffer::Usage, fixed parameter order in Image
constructor, fixed some function references. Added explicit references
to linkable stuff.
Encourages vectorization and generic usage even more. Some functions
were rewritten to make use of the new features, resulting in shorter and
more readable code. This also fixes the annoying naming collision with
WINAPI Rectangle() function.
The old Rectangle is now subclass of Range2D, is marked as deprecated
and will be removed in future release.
Also fixed unary RectangularMatrix::operator-() and Vector::operator-()
documentation (was stating that the operation is done in-place, which is
impossible.
Also updated all dependent classes to follow the change, such as Color
and Rectangle. Backwards compatibility for GCC 4.6 (with lack of support
for delegating constructors) will be done as non-constexpr constructor
using operator=().