…> so that Spectral and Opticks use the same opencv2 libraries.

git tag opencv2-1

…han older opencv. No other changes, just the #includes.

   2. Code/CMakeLists.txt make Ossim an optional package -- it doesn't ever seem to be used.
   3. Code/cmake/Modules/ConfigureQt5Qwt6.cmake simplify Qt5 package determination usingQt5_DIR variable consistent with Opticks' ConfigureQt5Qwt5.
   4. Code/cmake/Modules/FindQwt6ForQt5.cmake similar as ConfigureQt5Qwt6.cmake except spectral uses qwt6 which must always be
      compiled and installed separately on CentOS-7.
   5. Code/cmake/Modules/FindOpenCv.cmake, FindOssim, and Findproj are copied over from opticks for consistency.
   git tag opencv2-2

cmake 3.17.5
git tag opencv2-3

…tiff.cmake to make them identical with those in Opticks.

git tag opencv2-4