Remove prematureExit/exitStatus, and implement in task main loop

Use the previous commit on returning success from each task execution
function, and implement handling of errors in the main loop. Add a
script with which this is visible using Custom_Commands.

ci-scripts/tests/test-runner/test.xml

@@ -27,6 +27,9 @@
         <htmlTabIcon>wrench</htmlTabIcon>
         <TestCaseRequestedList>
  000001
+ 000002
+ 000003
+ 000004
         </TestCaseRequestedList>
         <TestCaseExclusionList></TestCaseExclusionList>
 
@@ -37,4 +40,29 @@
                 <command>true</command>
                 <command_fail>yes</command_fail>
         </testCase>
+
+        <testCase id="000002">
+                <class>Custom_Command</class>
+                <desc>This should fail</desc>
+                <node>localhost</node>
+                <command>false</command>
+                <command_fail>yes</command_fail>
+        </testCase>
+
+        <testCase id="000003">
+                <class>Custom_Command</class>
+                <desc>This should be skipped</desc>
+                <node>localhost</node>
+                <command>true</command>
+                <command_fail>yes</command_fail>
+        </testCase>
+
+        <testCase id="000004">
+                <class>Custom_Command</class>
+                <desc>This should be executed because marked so</desc>
+                <always_exec>true</always_exec>
+                <node>localhost</node>
+                <command>true</command>
+                <command_fail>yes</command_fail>
+        </testCase>
 </testCaseList>