Changed premake.lua to work with mingw.

Implemented array operations, not perfect but ok for tonight. closes #89

tests/mini/arrayops4.d

@@ -0,0 +1,29 @@
+void main()
+{
+    auto a = new float[1024];
+    auto b = new float[1024];
+    auto c = new float[1024];
+
+    for (auto i=0; i<1024; i++)
+    {
+        a[i] = i;
+        b[i] = i*2;
+        c[i] = i*4;
+    }
+
+    a[] = b[] + c[] / 2;
+
+    foreach(i,v; a)
+    {
+        assert(eq(v, b[i] + c[i] / 2));
+    }
+}
+
+float abs(float x)
+{
+    return x<0?-x:x;
+}
+bool eq(float a, float b)
+{
+    return abs(a-b) <= float.epsilon;
+}