Introduce evaluation of an environment variable to choose if all, only database or only database unit tests are to be executed.

This is mainly required on automated execution on Jenkins

autotest.sh

@@ -260,14 +260,27 @@ function execute_tests {
 	if [[ "$_XDEBUG_CONFIG" ]]; then
 		export XDEBUG_CONFIG=$_XDEBUG_CONFIG
 	fi
+	if [ -z "$TEST_SELECTION" ]; then
+		TEST_SELECTION='all'
+	fi
+	GROUP=''
+	if [ "$TEST_SELECTION" == "DB" ]; then
+		GROUP='--group DB'
+	fi
+	if [ "$TEST_SELECTION" == "NODB" ]; then
+		GROUP='--exclude-group DB'
+	fi
+
+	COVER=''
 	if [ -z "$NOCOVERAGE" ]; then
-		"${PHPUNIT[@]}" --configuration phpunit-autotest.xml --log-junit "autotest-results-$DB.xml" --coverage-clover "autotest-clover-$DB.xml" --coverage-html "coverage-html-$DB" "$2" "$3"
-		RESULT=$?
+		COVER='--coverage-clover "autotest-clover-$DB.xml" --coverage-html "coverage-html-$DB"'
+		"${PHPUNIT[@]}" --configuration phpunit-autotest.xml $GROUP --log-junit "autotest-results-$DB.xml" --coverage-clover "autotest-clover-$DB.xml" --coverage-html "coverage-html-$DB" "$2" "$3"
 	else
 		echo "No coverage"
-		"${PHPUNIT[@]}" --configuration phpunit-autotest.xml --log-junit "autotest-results-$DB.xml" "$2" "$3"
-		RESULT=$?
 	fi
+	echo "${PHPUNIT[@]}" --configuration phpunit-autotest.xml $GROUP $COVER --log-junit "autotest-results-$DB.xml" "$2" "$3"
+	"${PHPUNIT[@]}" --configuration phpunit-autotest.xml $GROUP $COVER --log-junit "autotest-results-$DB.xml" "$2" "$3"
+		RESULT=$?
 
 	if [ "$PRIMARY_STORAGE_CONFIG" == "swift" ] ; then
 		cd ..