Changed the runtest so that a value of 0 returned from csvdiff

indicates a successful test. Previously, it had been a 1. 
These tests in this branch weren't changed in my commit of last week.

test_problems/ChemEquil_ionizedGas/runtest

@@ -25,7 +25,7 @@ ${CANTERA_BIN}/csvdiff -a 1.0E-19 table.csv table_blessed.csv > diff_csv.txt
 retnStat_csv=$?
 
 eCode=1
-if test $retnStat_csv = "1"
+if test $retnStat_csv = "0"
 then
   eCode=0
   echo "Successful test comparison on " $testName
@@ -35,7 +35,7 @@ then
   fi
 else
   echo "Unsuccessful test comparison on " $testName " test"
-  if test $retnStat_csv != "1"
+  if test $retnStat_csv != "0"
   then
      echo "      csv files are different - see diff_csv.txt"
   fi

test_problems/cxx_ex/runtest

@@ -36,7 +36,7 @@ machType=`../../bin/get_arch`
 
 $CANTERA_BIN/csvdiff eq1.csv eq1_blessed.csv > eq1_test.out
 retnStat=$?
-if [ $retnStat = "1" ]
+if [ $retnStat = "0" ]
 then
   echo "successful csv comparison on eq1 test"
 else
@@ -57,7 +57,7 @@ fi
 
 $CANTERA_BIN/csvdiff tr1.csv tr1_blessed.csv > tr1_test.out
 retnStat=$?
-if [ $retnStat = "1" ]
+if [ $retnStat = "0" ]
 then
   echo "successful csv comparison on tr1 test"
   if [ $temp_success = "1" ]
@@ -82,7 +82,7 @@ fi
 
 $CANTERA_BIN/csvdiff tr2.csv tr2_blessed.csv > tr2_test.out
 retnStat=$?
-if [ $retnStat = "1" ]
+if [ $retnStat = "0" ]
 then
   echo "successful csv comparison on tr2 test"
   if [ $temp_success = "1" ]
@@ -116,7 +116,7 @@ fi
 
 $CANTERA_BIN/csvdiff -r 3.0E-3 kin1.csv kin1_blessed_tmp.csv > kin1_test.out
 retnStat=$?
-if [ $retnStat = "1" ]
+if [ $retnStat = "0" ]
 then
   echo "successful csv comparison on kin1 test"
   if [ $temp_success = "1" ]
@@ -150,7 +150,7 @@ fi
 
 $CANTERA_BIN/csvdiff kin2.csv kin2_blessed_tmp.csv > kin2_test.out
 retnStat=$?
-if [ $retnStat = "1" ]
+if [ $retnStat = "0" ]
 then
   echo "successful csv comparison on kin2 test"
   if [ $temp_success = "1" ]

test_problems/python/runtest

@@ -70,7 +70,7 @@ fi
 
 $CANTERA_BIN/csvdiff diamond.csv diamond_blessed.csv > diamond_test.out
 retnStat=$?
-if [ $retnStat = "1" ]
+if [ $retnStat = "0" ]
 then
   echo "successful csv comparison on diamond test"
   if [ $temp_success = "1" ]