[svn r58] Fixed cond expression resulting in a non-basic type.

Fixed identity expression for dynamic arrays.
Revamped the system to keep track of lvalues and rvalues and their relations.
Typedef declaration now generate the custom typeinfo.
Other bugfixes.

test/condexp1.d

@@ -0,0 +1,12 @@
+module condexp1;
+
+void main()
+{
+    char[] a = "hello";
+    char[] b = "world";
+    int i = 42;
+    {
+    char[] c = i > 50 ? b : a;
+    assert(c is a);
+    }
+}