FIX: use btScalar instead of float, otherwise double precision build breaks

FIX: make Maya plugin compile for Maya 8.0
FIX: btDbvt SSE doesn't compile for double precision builds

src/BulletCollision/BroadphaseCollision/btDbvt.h

@@ -62,7 +62,7 @@ subject to the following restrictions:
 // Specific methods implementation
 
 //SSE gives errors on a MSVC 7.1
-#if (defined (WIN32) && (_MSC_VER) && _MSC_VER >= 1400)
+#if (defined (WIN32) && (_MSC_VER) && _MSC_VER >= 1400) && (!defined (BT_USE_DOUBLE_PRECISION))
 #define DBVT_SELECT_IMPL		DBVT_IMPL_SSE
 #define DBVT_MERGE_IMPL			DBVT_IMPL_SSE
 #define DBVT_INT0_IMPL			DBVT_IMPL_SSE

src/BulletCollision/CollisionDispatch/btBoxBoxDetector.cpp

@@ -226,9 +226,9 @@ void cullPoints2 (int n, btScalar p[], int m, int i0, int iret[])
     a = btScalar(j)*(2*M__PI/m) + A[i0];
     if (a > M__PI) a -= 2*M__PI;
     btScalar maxdiff=1e9,diff;
-#if defined(DEBUG) || defined (_DEBUG)
-    *iret = i0;			// iret is not allowed to keep this value
-#endif
+
+    *iret = i0;			// iret is not allowed to keep this value, but it sometimes does, when diff=#QNAN0
+
     for (i=0; i<n; i++) {
       if (avail[i]) {
 	diff = btFabs (A[i]-a);