ENH: Sync python scripts with python3.

Fix failing ITK*InDoxygenGroup tests due to
python API changes from python2.x to
python3.x.
ENH: Sync python scripts with python3.

Fix failing ITK*InDoxygenGroup tests due to
python API changes from python2.x to
python3.x.
Merge branch 'Python3Release' into release

This is already in master.  cherry-picking.
Merge topic 'SyncWithPython3'

ae94983 ENH: Sync python scripts with python3.
Merge branch 'release'
COMP: Fix all valid cppcheck warnings in "Module/Registration" directory

The cppcheck is run inside the ITK/Module/Core directory and all the
valid cppcheck issues are fixed.

Some of the cppcheck warnings are related to the functions that are not
used, but they may be used later by users. Such a warning is an example of
invalid warnings.

The titles of major fixed issues are listed below:

- prefix ++/-- operators are preferred for non-primitive types.
- initialization to assignment is preferred.
- if possible, the scope of variables are reduced.
- initialization of variable in initialization list is preferred than
assigning variable in constructor body.

All the ITK tests are passed after the above changes.

Change-Id: If152f4b061f5e99ef39af9aa2685f63de5630344
Merge topic 'registration_cppcheck_perf'

76d7f46 COMP: Fix all valid cppcheck warnings in "Module/Registration" directory
COMP: Fix all valid cppcheck warnings in ITK (last patch)

  Previously five patches were sent about fixing cppcheck warnings in
  ITK/Module directory.

  At the current patch, all other valid remained cppcheck warnings in
  the ITK directory are fixed. All the remained valid warnings were from
  Example/ directory.

  One example of invalid warnings are those that are about unused
  functions. This functions are not used in static analysis, but the are
  used by users in real applications.

  The fixed issues are generally about the following topics:

  1) In definition of class A:
    the 'A::operator=' should return 'A &'. However, they would return
    viod.

  2) Prefix ++/-- operators are preferred for non-primitive types.

  3) Initialization to assignment is preferred.

  4) If possible, variables are passed by reference.(This warning mostly
    happens about Exception catching).

  5) Emptiness of variables are checked efficiently using the empty()
  function.

  6) Unused variables are removed.

  All the ITK tests are passed after the above changes.

Change-Id: I00e4804b4e26dbc2e709d17a82279713be36f307
Merge topic 'NO_module_cppcheck'

a379365 COMP: Fix all valid cppcheck warnings in ITK (last patch)