ENH: Adding some ImageIO libraries as shared

By making these libraries shared they will only be registered once
into the ImageIOFactory.

Change-Id: Ie11f9ea9975bb42463894201ae308e0dcbaee95b
BUG: Uninitialized scalar field

Coverity detected uninitialied variables that resulted if denominators
were zero. The resulting variables were not defined for the zero
denominator logic.

Change-Id: I5b8bcea7e97f9394cbd6be7d8d8ea1ed6eeaf633
Merge topic 'ImageIOSharedLibraries'

a5d8f659 ENH: Adding some ImageIO libraries as shared
Merge topic 'Coverity_UninitializedScalarVariable'

17726340 BUG: Uninitialized scalar field