system_test was taking too long to run.

SPARSE_NORMAL_CHOLESKY with CXSparse on the fairly small
bundle adjustment problem used in system_test is too expensive
to be useful as a test. It takes up too much memory and time
making the test fail on client computers < 4G of RAM.

These tests have been deleted.

Change-Id: Id015671536afd7013f5b7d19c39d64c2748884ad

internal/ceres/system_test.cc

diff --git a/internal/ceres/system_test.cc b/internal/ceres/system_test.cc
index 8e2f5eb..3eaebc3 100644
--- a/internal/ceres/system_test.cc
+++ b/internal/ceres/system_test.cc
@@ -500,10 +500,6 @@
 #endif  // CERES_NO_SUITESPARSE
 
 #ifndef CERES_NO_CXSPARSE
-  CONFIGURE(SPARSE_NORMAL_CHOLESKY, CX_SPARSE, NATURAL, IDENTITY, 1);
-  CONFIGURE(SPARSE_NORMAL_CHOLESKY, CX_SPARSE, USER,    IDENTITY, 1);
-  CONFIGURE(SPARSE_NORMAL_CHOLESKY, CX_SPARSE, SCHUR,   IDENTITY, 1);
-
   CONFIGURE(SPARSE_SCHUR,           CX_SPARSE, USER,    IDENTITY, 1);
   CONFIGURE(SPARSE_SCHUR,           CX_SPARSE, SCHUR,   IDENTITY, 1);
 #endif  // CERES_NO_CXSPARSE