BUG: Use new VNL include directory variables.
BUG: Use new VNL include directory variables.

These variables changed in recent upstream VNL. Keep the old variables for
backwards compatibility. Addresses:

  /home/matt/src/vxl/vcl/vcl_compiler.h:121:31: fatal error:
  vcl_config_manual.h: No such file or directory

  /home/matt/src/vxl/core/vnl/vnl_error.h:10:28: fatal error:
  vnl/vnl_export.h: No such file or directory

with ITK_USE_SYSTEM_VXL enabled.

Change-Id: I7c8ea9bbb195e176cde3e8969075bef4906073c2

spinicist/ITK,vfonov/ITK,LucasGandel/ITK,stnava/ITK,fbudin69500/ITK,thewtex/ITK,Kitware/ITK,thewtex/ITK,richardbeare/ITK,Kitware/ITK,zachary-williamson/ITK,thewtex/ITK,zachary-williamson/ITK,InsightSoftwareConsortium/ITK,hjmjohnson/ITK,malaterre/ITK,richardbeare/ITK,zachary-williamson/ITK,PlutoniumHeart/ITK,vfonov/ITK,spinicist/ITK,zachary-williamson/ITK,spinicist/ITK,stnava/ITK,fbudin69500/ITK,BRAINSia/ITK,vfonov/ITK,thewtex/ITK,richardbeare/ITK,LucasGandel/ITK,hjmjohnson/ITK,PlutoniumHeart/ITK,richardbeare/ITK,spinicist/ITK,Kitware/ITK,PlutoniumHeart/ITK,richardbeare/ITK,spinicist/ITK,zachary-williamson/ITK,zachary-williamson/ITK,malaterre/ITK,fbudin69500/ITK,LucasGandel/ITK,InsightSoftwareConsortium/ITK,malaterre/ITK,blowekamp/ITK,PlutoniumHeart/ITK,InsightSoftwareConsortium/ITK,hjmjohnson/ITK,InsightSoftwareConsortium/ITK,spinicist/ITK,zachary-williamson/ITK,fbudin69500/ITK,Kitware/ITK,PlutoniumHeart/ITK,hjmjohnson/ITK,BRAINSia/ITK,blowekamp/ITK,Kitware/ITK,malaterre/ITK,LucasGandel/ITK,stnava/ITK,BRAINSia/ITK,richardbeare/ITK,vfonov/ITK,stnava/ITK,hjmjohnson/ITK,InsightSoftwareConsortium/ITK,malaterre/ITK,thewtex/ITK,stnava/ITK,fbudin69500/ITK,InsightSoftwareConsortium/ITK,malaterre/ITK,thewtex/ITK,Kitware/ITK,stnava/ITK,stnava/ITK,PlutoniumHeart/ITK,hjmjohnson/ITK,BRAINSia/ITK,spinicist/ITK,LucasGandel/ITK,LucasGandel/ITK,PlutoniumHeart/ITK,BRAINSia/ITK,malaterre/ITK,LucasGandel/ITK,InsightSoftwareConsortium/ITK,spinicist/ITK,vfonov/ITK,zachary-williamson/ITK,spinicist/ITK,hjmjohnson/ITK,zachary-williamson/ITK,vfonov/ITK,fbudin69500/ITK,stnava/ITK,richardbeare/ITK,blowekamp/ITK,fbudin69500/ITK,vfonov/ITK,malaterre/ITK,vfonov/ITK,stnava/ITK,blowekamp/ITK,fbudin69500/ITK,blowekamp/ITK,thewtex/ITK,blowekamp/ITK,BRAINSia/ITK,blowekamp/ITK,malaterre/ITK,Kitware/ITK,PlutoniumHeart/ITK,LucasGandel/ITK,vfonov/ITK,BRAINSia/ITK,blowekamp/ITK