ENH: find language packages to set default laguages to wrap
ENH: find language packages to set default laguages to wrap

Each language is searched for with a non-required find_package. If the
requred laguage packages are found then the defaut for wrapping that
language is enabled.

SIMPLEITK-29

SimpleITK/Staging,SimpleITK/Staging,SimpleITK/Staging,SimpleITK/Staging,SimpleITK/Staging,SimpleITK/Staging,SimpleITK/Staging