BUG: Change python __invert__ to bitwise not

Compatibility: This changes the behavior of the operator(~) from a
logical not to a bitwise not.

The ITK documentation on these (&^|) operators was incorrectly calling them
"logical" when the were bitwise, but the Not filter was acutally a
logical. So a new bitwise not functor and SimpleITK filter was created
and is not utilized for python.

Change-Id: Ifa5943f488fd40bb05977bfd6356417266ce47b9
BUG: Update C++ operator~ to use BitwiseNot

Updated tests for the new operation.

Note: This changes the behavior of an existing operator and is a
compatibility issue.

Change-Id: Ic26a36b1f65bf55ca1a534ba0e4da75d42f9babd
Merge topic 'SIMPLEITK-391_CorrectBitwiseNotOperator' into next

8dabcdc0 BUG: Update C++ operator~ to use BitwiseNot
2cf80e6a BUG: Change python __invert__ to bitwise not