Improve math module (#396)

* Improve math module

- Mark almost everything constexpr
- Equality (a == b) is now exact, down to the bit level. If you want approximate equality use the new ApproxEqual method/static method
- Rename Nz::Extend to Nz::Extent
- Removed Make[] and Set[] methods in favor of their static counterpart and operator=

include/Nazara/Utility/RichTextDrawer.inl

@@ -170,12 +170,11 @@ namespace Nz
 
 	inline void RichTextDrawer::ClearGlyphs() const
 	{
-		m_bounds.MakeZero();
+		m_bounds = Rectf::Zero(); //< Compute bounds as float to speedup bounds computation (as casting between floats and integers is costly)
 		m_lastSeparatorGlyph = InvalidGlyph;
 		m_lines.clear();
 		m_glyphs.clear();
 		m_glyphUpdated = true;
-		m_bounds.MakeZero(); //< Compute bounds as float to speedup bounds computation (as casting between floats and integers is costly)
 	}
 
 	inline void RichTextDrawer::ConnectFontSlots()