Working test cases for the sophisticated matrix library example from the manual

Fixed the dot operator when used within return types (see tgenericdotrettype)
Fixed the matching of generic concepts aliases used with the implicit generics style

tests/concepts/tmatrixlib.nim

@@ -0,0 +1,31 @@
+discard """
+output: "0"
+"""
+
+import matrix, matrixalgo
+
+import typetraits # XXX: this should be removed
+
+var m: Matrix[3, 3, int]
+var projectionMatrix: Matrix[4, 4, float]
+
+echo m.transposed.determinant
+setPerspectiveProjection projectionMatrix
+
+template ok(x) = assert x
+template no(x) = assert(not x)
+
+static:
+  ok projectionMatrix is AnyTransform3D
+  no m is AnyTransform3D
+  
+  type SquareStringMatrix = Matrix[5, 5, string]
+  
+  ok SquareStringMatrix is AnyMatrix
+  ok SquareStringMatrix is AnySquareMatrix
+  no SquareStringMatrix is AnyTransform3D
+  
+  ok Matrix[5, 10, int] is AnyMatrix
+  no Matrix[7, 15, float] is AnySquareMatrix
+  no Matrix[4, 4, int] is AnyTransform3D
+