utest-based tests.

(bzr r6976)

(bzr r6495)

    src/libcola/gradient_projection.cpp, src/libvpsc/generate-constraints.cpp,
    src/libnr/nr-types.cpp, src/libnr/nr-point-fns-test.cpp, src/isnan.h,
    src/libnr/nr-point-fns.cpp, src/libnr/in-svg-plane-test.cpp,
    src/doxygen-main.cpp, src/display/nr-filter-composite.cpp,
    src/display/nr-filter-merge.cpp, src/display/nr-filter-gaussian.cpp,
    src/display/bezier-utils.cpp, src/Makefile_insert, src/eraser-context.cpp,
    src/dyna-draw-context.cpp, src/tweak-context.cpp, src/sp-namedview.cpp,
    src/libnr/in-svg-plane-test.h, src/libnr/nr-point-fns-test.h,
    src/mod360-test.h, src/CMakeLists.txt, src/2geom/linear.h:

    Properly fix the conflicting isnan.h problem:
      1) Update src/2geom/isnan.h to match newest Inkscape src/isnana.h
         (Also commited this change to lib2geom project repository)
      2) Remove Inkscape's src/isnan.h
      3) Update all files to include src/2geom/isnan.h instead of src/isnan.h

(bzr r6013)

(bzr r5823)

(bzr r1)