Merge branch 'SIMPLEITK-525_EnableDeletionOfCommandProcessExists' into SIMPLEITK-521_AddInitialRegistrationComponents

Change-Id: I7214c9bcad29358325189fda89ea80a197d6e609
Change method to AddITKObserver

Updated for renamed method overridden from ProcessObject.

Change-Id: I700ff682bcb19a255e01a998eb6b10351d8a6c64
Move CreateITKEventObject to a protected method of ProcessObject

Change-Id: I8605dc043728ad2297b78e526484d765ee19f72a
Use Event generator method

Change-Id: I46a5d23e045acec887efc52a401b35d789761a0e
Implement RemoveITKObserver for iteration events

The ImageRegistrationMethod overrides the adding and removal of
iteration events to add them to the optimizer as opposed to the
process object.

Change-Id: If6d9d2ae60d2b23b2dd5b5589fb7efb0a8b71f2a
Merge topic 'SIMPLEITK-521_AddInitialRegistrationComponents' into next

9d2ad588 Implement RemoveITKObserver for iteration events
f7ab8d0c Use Event generator method
cb5f508d Move CreateITKEventObject to a protected method of ProcessObject
5210dd72 Change method to AddITKObserver
74b27d3b Merge branch 'SIMPLEITK-525_EnableDeletionOfCommandProcessExists' into SIMPLEITK-521_AddInitialRegistrationComponents
COMP: fix syntax error in test

Change-Id: If1c188ebb6629fcfebb46f8d14766b7fa8599d70
Updated documentation for in ProcessObject for command related methods

Change-Id: I4808ea6de9989b380777b414528b9118473e3ba7
Merge topic 'SIMPLEITK-525_EnableDeletionOfCommandProcessExists' into next

68e95d0b Updated documentation for in ProcessObject for command related methods
dc6a58d8 COMP: fix syntax error in test