Add a resampling filter

That filter use the current vtkProbe filter to probe the input dataset by
creating an image data that fulfill the sampling specification of the user.
This simplify a common type of processing that would otherwise require
a more complex workflow.

Change-Id: I3b9c6557bbdfa9d6553ceebcc3a0741960fec72e
Add JSON writer for ImageData

This allow user to dump an Image dataset into a JSON format.

Change-Id: I96d41f37c5bad8a8c3ff3f815ad6a39cb6c6490f
Extend vtkImageMapToColors to support Mask color and Non Active Scalar input

If a vtkValidPointMask char array is available. Then the NaN color
option will apply and that color will be used for all value that
are masked by that array.

In case of RGBA, the NaN color will use its 4 components, otherwise 3 for RGB,
2 for Luminance+Alpha and 1 for Luminance.

Change-Id: Ica51bb4eea44fb74eb87f4a6f1d7cdbccb609269
Merge topic 'add_image_base_filter' into master

ca29c4e9 Add JSON writer for ImageData
c4821d4b Add a resampling filter
Merge topic 'image-to-color-extension' into master

ce554a58 Extend vtkImageMapToColors to support Mask color and Non Active Scalar input