Refactor, separate docs from headers, add ru docs

Doxygen kind'a sucks and I need multilanguage documentation, so I did
that. Also, separated massive Math.h file into smaller files.

include/BH/Math/Vec2i.h

@@ -0,0 +1,52 @@
+#ifndef BH_MATH_VEC2I_H
+#define BH_MATH_VEC2I_H
+
+#include "../Common.h"
+
+void BH_Vec2iAdd(const int a[2],
+                 const int b[2],
+                 int out[2]);
+
+
+
+void BH_Vec2iSub(const int a[2],
+                 const int b[2],
+                 int out[2]);
+
+
+
+void BH_Vec2iMul(const int a[2],
+                 const int b[2],
+                 int out[2]);
+
+
+
+void BH_Vec2iScale(const int a[2],
+                   int b,
+                   int out[2]);
+
+
+
+void BH_Vec2iMulAdd(const int a[2],
+                    const int b[2],
+                    const int c[2],
+                    int out[2]);
+
+
+
+void BH_Vec2iNegate(const int in[2],
+                    int out[2]);
+
+
+
+void BH_Vec2iMin(const int a[2],
+                 const int b[2],
+                 int out[2]);
+
+
+
+void BH_Vec2iMax(const int a[2],
+                 const int b[2],
+                 int out[2]);
+
+#endif /* BH_MATH_VEC2I */