Tested:
$ cmake -DASSIMP_DOUBLE_PRECISION=1 -DASSIMP_BUILD_MDL_IMPORTER=0 ..; make
The MDL importer is disabled due to the fact that there is some float-only code
in MDL. This also means bin/assimp and bin/unit would not link successfully with
the above build flags.
Changed copyright end year to 2020 in every reference "Copyright (c) 2006-XXXX, assimp team".
Changed copyright end year to 2020 in every reference "Copyright (c) 2006-XXXX, ASSIMP Development Team".
Changed copyright end year to 2020 in LICENCE.rtf.
Changed copyright end year in CMakeFiles.txt files and any other places referencing Assimp with a copyright start and end year.