BUG: Correctly re-throw exception to restore AbortEvent, ProcessAborted

The abort exception was incorrectly being re-thrown as pointer to an
exception instead of re-throwing the exception by using the "throw"
keyword without an argument. The AbortEvent was never emitted before
now it is. Other cases of incorrect exceptions re-throws were grep and
corrected.

Change-Id: I7f858640739d49612d9f009f00f6a0a2548088af
COMP: SimpleITK linkage failure

When building with clang on 10.9 where ITKv4 is a shared library,
a linking error occured for unfound symbols: NumericTraits< OutputPixelType >::Zero
but using the NumericTraits< OutputPixelType >::ZeroValue()
allows linkage to occur properly.

Change-Id: I496a41c102960b60c461adefdccc373b39dabb03
Merge branch 'simpleitk-related' into release

Change-Id: I8e4ff28422ae506207b39e0de00aab9e2121d81b