Shaders: doc++
Shaders: textured version of Flat shader.
Separated deprecated API and deprecated GL API in the docs.

New code may not use deprecated API, but for some reasons (support
for old GL versions) might use deprecated GL API.
Doc++
Initial support for ability to disable building of deprecated APIs.

CMake option `BUILD_DEPRECATED`, enabled by default, exposed as
`MAGNUM_BUILD_DEPRECATED` to users both in CMake and C++ code.
Disable deprecated API if MAGNUM_BUILD_DEPRECATED is set.

Causes the compilation to fail.
Fix build without MAGNUM_BUILD_DEPRECATED.

Updated Buffer test to check all data setting functions.
Doc++
Moved RGB(A) accessors from Color to Vector.

This functionality doesn't depend on anything from Color itself and it
is inconvenient to cast the vector to Color just to use them.
Moved RGB(A) accessors from swizzle() to Math::swizzle().

As Math::Vector now contains them, there is no need to restrict them
from the original swizzle implementation.
Math: document include in test.
Deprecate swizzle() in favor of Math::swizzle().

All the functionality is moved to Math::swizzle() and the result is
casted to given type only if its header is included. Thus it is possible
to remove include dependency on Color. The original swizzle() is now
just an alias marked as deprecated and will be removed in future
release.
Use ninja for development PKGBUILD.

OMG it's so fast.
Platform: print {CORRADE,MAGNUM}_BUILD_DEPRECATED flags in magnum-info.
SceneGraph: move Implementation::Transformation declaration to SceneGraph.h.

Previously it caused compilation failure when only Object.h was included.