Squish: Ensure clean state after test run...

...depending on the environment and the present terminal variations
it might be possible that QC leaves terminals with still running
qtcreator_process_stubs open.
Ensure to kill these (and automatically close their terminals).

Task-number: QTCREATORBUG-15749
Change-Id: I0cdbaf000c355443289bf827034ad9884efc2ce7
Reviewed-by: Robert Loehning <robert.loehning@theqtcompany.com>

tests/system/shared/qtcreator.py

@@ -33,6 +33,7 @@ import subprocess;
 import sys
 import errno;
 from datetime import datetime,timedelta;
+import __builtin__
 
 srcPath = ''
 SettingsPath = ''
@@ -116,6 +117,16 @@ def waitForCleanShutdown(timeOut=10):
                     shutdownDone=True
             if not shutdownDone and datetime.utcnow() > endtime:
                 break
+        if platform.system() == 'Linux' and JIRA.isBugStillOpen(15749):
+            pgrepOutput = getOutputFromCmdline('pgrep -f qtcreator_process_stub')
+            pids = pgrepOutput.splitlines()
+            if len(pids):
+                print("Killing %d qtcreator_process_stub instances" % len(pids))
+            for pid in pids:
+                try:
+                    os.kill(__builtin__.int(pid), 9)
+                except OSError: # we might kill the parent before the current pid
+                    pass
 
 def checkForStillRunningQmlExecutable(possibleNames):
     for qmlHelper in possibleNames: