STYLE: Capture stderr/stdout for eigen3 config
STYLE: Capture stderr/stdout for eigen3 config

The eigen3 internal configuration was writting to
stderr and stdout which corrupted the ncurses
interface of ccmake.  Capture those items and
report as cmake info messages.

Kitware/ITK,malaterre/ITK,hjmjohnson/ITK,LucasGandel/ITK,thewtex/ITK,InsightSoftwareConsortium/ITK,BRAINSia/ITK,richardbeare/ITK,BRAINSia/ITK,richardbeare/ITK,BRAINSia/ITK,Kitware/ITK,malaterre/ITK,InsightSoftwareConsortium/ITK,InsightSoftwareConsortium/ITK,BRAINSia/ITK,vfonov/ITK,malaterre/ITK,LucasGandel/ITK,Kitware/ITK,malaterre/ITK,InsightSoftwareConsortium/ITK,thewtex/ITK,vfonov/ITK,InsightSoftwareConsortium/ITK,hjmjohnson/ITK,hjmjohnson/ITK,LucasGandel/ITK,Kitware/ITK,malaterre/ITK,Kitware/ITK,richardbeare/ITK,malaterre/ITK,vfonov/ITK,BRAINSia/ITK,vfonov/ITK,vfonov/ITK,Kitware/ITK,malaterre/ITK,InsightSoftwareConsortium/ITK,malaterre/ITK,vfonov/ITK,thewtex/ITK,BRAINSia/ITK,richardbeare/ITK,hjmjohnson/ITK,richardbeare/ITK,LucasGandel/ITK,LucasGandel/ITK,hjmjohnson/ITK,InsightSoftwareConsortium/ITK,LucasGandel/ITK,vfonov/ITK,Kitware/ITK,thewtex/ITK,LucasGandel/ITK,vfonov/ITK,richardbeare/ITK,vfonov/ITK,LucasGandel/ITK,malaterre/ITK,BRAINSia/ITK,richardbeare/ITK,hjmjohnson/ITK,thewtex/ITK,thewtex/ITK,thewtex/ITK,hjmjohnson/ITK