BUG: TestingExtractSliceImageFilter lacked test.

In this patch we add a unit test for the itkTestingExtractSliceImageFilter
class.

NOTE: The unit test uncovered a bug in SetExtractionRegion. The
dimension of the output size and index were being exceeded, causing a
crash on Windows systems.

This class is critical, given that it is used as part of the testing
infrastructure for the rest of the toolkit.

Change-Id: I0b5a80f88f22ccd754c1a6f433a2b0a57475f69a
COMP: Remove vcl_time and vcl_clock

These vcl methods were initialliy use because not al systems provided
a consistent interface. Now, clock_t, time_t, clock() and time() are
well supported. The complex logic in the vcl interface is no longer
needed.

Change-Id: I40975e30605bde1db389b4c7bec342d9f7ae5405
COMP: Update PCRE to 8.35

Will fix some more warnings under Windows for the Python Wrappings.

Change-Id: I99a5b4cd27eb8e391f9175f5c16d3b4aeae516e3
Merge topic 'Remove_vcl_time_vcl_clock'

1f19aa00 COMP: Remove vcl_time and vcl_clock
BUG: Match behavior of SimpleFastMutexLock on different platforms (#ITK-3248)

The WinAPI and the pthread implementation behaved differently regaring recursive locking.

The WinAPI implementation used "InitializeCriticalSection" and "EnterCriticalSection" which let the thread holding the mutex call EnterCriticalSection again without blocking:
http://msdn.microsoft.com/en-us/library/windows/desktop/ms682608%28v=vs.85%29.aspx

In contrast the pthread implementation used pthread_mutex_init and pthread_mutex_lock whose behavior concerning this matter was dependent on the initialization parameters of the mutex. The default (which was used in ITK) doesn't allow recursive locking:
http://pubs.opengroup.org/onlinepubs/7908799/xsh/pthread_mutex_lock.html

I suggest to adapt the pthread implementation because it seems to me that the current behavior of the WinAPI implementation is the one expected by most users.

Change-Id: Ic75fab3eedd1b457c531668b7786501a139426ba
Merge topic 'PCRE8.35'

39d326e3 COMP: Update PCRE to 8.35
Merge topic 'itkTestingExtractSliceImageFilter_CodeCoverage'

cba75dac BUG: TestingExtractSliceImageFilter lacked test.
Merge topic '3248-platform-dependent-mutex'

f8d8c7b9 BUG: Match behavior of SimpleFastMutexLock on different platforms (#ITK-3248)