ENH: Better SWIG dependancies, rebuild if any .i file changes
ENH: Better SWIG dependancies, rebuild if any .i file changes

Modification of language-specific files now trigger a rebuild.

SIMPLEITK-38 #resolve

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