Fix debugging of terminal applications on Linux

On modern linux distributions (Ubuntu >= 10.10, Debian >= Wheezy),
trying to debug a terminal application fails, with
"ptrace: Operation not permitted".

In order to allow the debugger to attach to the created process, the
process itself needs to inform the kernel of the debugging process.

Task-number: QTCREATORBUG-3509
Change-Id: I68670426fad18cbe3b7cce9d57633e58e631e025
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: hjk <hjk121@nokiamail.com>

src/libs/utils/consoleprocess_unix.cpp

@@ -162,6 +162,7 @@ bool ConsoleProcess::start(const QString &program, const QString &args)
               << msgPromptToClose()
               << workingDirectory()
               << (d->m_tempFile ? d->m_tempFile->fileName() : QString())
+              << QString::number(getpid())
               << pcmd << pargs.toUnixArgs();
 
     QString xterm = allArgs.takeFirst();