COMP: Fix itkVnlComplexToComplexFFTImageFilter wrapping

The name of the filter was not correctly defined in the .wrap file.
This generated the following error:

[ 15%] Generating itkVnlComplexToComplexImageFilter.xml
build/Wrapping/Modules/ITKFFT/itkVnlComplexToComplexImageFilter.cxx:20:47: error: itkVnlComplexToComplexImageFilter.h: No such file or directory

Change-Id: I7c92ee14deb524c69ec471287d2025795f04079f
COMP: Do not hide pygccxml warnings

Before the ITK 4.6 release, the pygccxml warnings were disabled,
to prevent the cluttering of the dashboard with warnings.
Normally, all the warnings have been fixed in pygccxml v1.6.0.
Re-enable warnings, so that we can fix the remaining ones. See ITK-3305

Change-Id: Ibf4d45b847e1e0cfcff7de2887a333d29c655bc5
Merge topic 'VnlComplexToComplexFFTImageFilterWrapping'

7a9ff891 COMP: Fix itkVnlComplexToComplexFFTImageFilter wrapping
Merge topic 'AllowpygccxmlWarnings'

ebe86a8e COMP: Do not hide pygccxml warnings