Added `SDL2/Texture` with `SDL2::Texture < vulture::Texture` empty class
`SDL2::Texture` now overrides `load(renderer(SDL2), name)` method
`SDL2::Texture` now overrides `color` accessors
Added `graphics/SDL2/Texture` header
Added empty definition of `SDL2::Texture::load` method
Umgh, im want to override only `Texture::color` setter in `SDL2::Texture`
Shh... + texture_handle typedef + _handle
Added definition of `SDL2::Texture::color(val)`