Import OCCT 6.7.1

 Remove unneeded folders, they are very large:
   data samples doc dox

 # Remove useless WOK folders
 rm -rf drv/*/.adm

 # Fix permissions (on Unix):
 find * -type f -exec chmod a-x {} \;

 # Autotools scripts
 chmod a+x build_configure

 # Windows scripts
 find adm/msvc  -type f -exec chmod a+x {} \;

 # Shell and bat scripts
 chmod a+x \
    adm/templates/draw.sh  \
    adm/templates/draw.bat  \
    adm/templates/env.sh.in  \
    adm/templates/env.bat.in  \
    adm/templates/sample.bat  \
    codeblocks.sh  \
    custom.bat  \
    custom.sh.in  \
    draw.bat  \
    draw.sh  \
    env.bat  \
    env.sh  \
    gendoc.bat  \
    gendoc  \
    msvc.bat  \
    xcode.sh