Implements a new design for the shader uniform API.
* Added Shader::setUniform() and Shader::setUniformArray() overloads for the following types:
-> scalars: float, int, bool
-> vectors: 2D, 3D, 4D
-> matrices: 3x3, 4x4
-> arrays of basic types
-> samplers (sf::Texture)
-> conversions for SFML types (sf::Transform, sf::Color)
* Added sf::Glsl namespace with GLSL-equivalent types
* Deprecated Shader::setParameter() overloads
Other related changes:
* Refactored sf::Shader internals to avoid code duplication
* Improved documentation
* Added SFML_DEPRECATED macro to Doxyfile
* Defined _SCL_SECURE_NO_WARNINGS to disable std::copy() warnings on MSVC
