Use nsstd wrapper for tr1::function and bind methods

Change-Id: If2e902247f4db1c22c585f7ad7cdec351f0357c5
Use 1% of pixels for spacial samples in the mutual information metric

This was being incorrectly set to 0, which got changed to 1 sample in
the metric.

Change-Id: I9bdbc32a9b9c89dc7d5d50e74b63c5e6289d8be5
Merge topic 'SIMPLEITK-521_AddInitialRegistrationComponents' into next

d1336bf7 Use 1% of pixels for spacial samples in the mutual information metric
86035e6d Use nsstd wrapper for tr1::function and bind methods