Fix conflicts between ext-inter and cb4x4 modes

Resolve the broken coding pipeline in ext-inter experiment when
cb4x4 mode is enabled. Turn off rectangular inter-intra mode.
This needs some more work to hook up. Given that it gives fairly
limited coding performance gains, disable it for the moment.

BUG=aomedia:309

Change-Id: I9b406df6183f75697bfd4eed5125a6e9436d84b0
diff --git a/av1/encoder/wedge_utils.c b/av1/encoder/wedge_utils.c
index e45a6a0..e6edbb6 100644
--- a/av1/encoder/wedge_utils.c
+++ b/av1/encoder/wedge_utils.c
@@ -53,7 +53,7 @@
                                         const uint8_t *m, int N) {
   uint64_t csse = 0;
   int i;
-  assert(N % 64 == 0);
+
   for (i = 0; i < N; i++) {
     int32_t t = MAX_MASK_VALUE * r1[i] + m[i] * d[i];
     t = clamp(t, INT16_MIN, INT16_MAX);
@@ -97,8 +97,6 @@
                                     int64_t limit) {
   int64_t acc = 0;
 
-  assert(N % 64 == 0);
-
   do {
     acc += *ds++ * *m++;
   } while (--N);
@@ -122,8 +120,6 @@
                                        const int16_t *b, int N) {
   int i;
 
-  assert(N % 64 == 0);
-
   for (i = 0; i < N; i++)
     d[i] = clamp(a[i] * a[i] - b[i] * b[i], INT16_MIN, INT16_MAX);
 }