Cherry-picked r6957 (hicalbeta's NonLinearLSQ.cpp gsl changes) into IPCE. This...

Cherry-picked r6957 (hicalbeta's NonLinearLSQ.cpp gsl changes) into IPCE. This allows hicalbeta to compile with new gsl library added to local third-party areas.

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/branches/ipce@7048 41f8697f-d340-4b68-9986-7bafba869bb8