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
BUG: Adding export specification to Exception objects

The ProcessAbort exception was not being handled correcly accross
compilation units with shared libraries.

The ProcessAborted exception was not exported. This causes there to be
distinct objects type of the same name to exist in different
compilation units. Therefore catches of this exception do not
correctly occur across compilation units. Specifically, the
ProcessObject is not catching the exception causing to AbortEvent to
occur.

Change-Id: Ie074699de15be7461e41c8e52a75bb0b710c576a
Merge topic 'FixExceptionLinkageForAbort'

80216068 BUG: Adding export specification to Exception objects
d7b9a0aa Merge branch 'simpleitk-related' into release
6c23e1da COMP: SimpleITK linkage failure
02468a31 BUG: Correctly re-throw exception to restore AbortEvent, ProcessAborted