Update template to document active measurements

Active measurements can be accessed during execution, and are not
documented as such.

Change-Id: I198dde24514c2f185d782455b584488dc838db63
Adding Wrapping of DemonsRegistrationFilter

Currently this filter is missing the optional input for an initial
deformation field. This is JIRA issue SIMPLEITK-429.

Change-Id: I4f93c2116a07cb8a086da37da7a1d5c4bd28dcba
Adding demos registration example.

Change-Id: I7f3702292e71263ceeb4a4f6812f376715f0e4a3
Changing input image to be gray scale.

Change-Id: I650de447395c206a023f524243e1073785810a06
Change output pixel type to VectorFloat64

This makes the output deformation field compatible with the transform
class.

Change-Id: Id4994534cdbb5e2e58bb20a275192b1527f6fca6
Support any pixel type for demons example

Change-Id: If48640f4b2ea4e7d48251ef0b4efeed9eb196c26
Adding test for demons registration filter

Change-Id: Ib44e3fba53654165e4d0e4737126f4cd2c4ef66f
Merge topic 'SIMPLEITK-426_WrapDeformationFieldFilters' into next

b5cc0593 Adding test for demons registration filter
fcb01ba1 Support any pixel type for demons example
700556d7 Change output pixel type to VectorFloat64
71e82560 Changing input image to be gray scale.
511bcce8 Adding demos registration example.
ed5310c0 Adding Wrapping of DemonsRegistrationFilter
059978f9 Update template to document active measurements