new sharing feature
change error message
delete useless code
add documentation
debug only of DEBUG flag is set
Revert "debug only of DEBUG flag is set"

This reverts commit a7fe7fe96bd325f46aa65bab75e58eea2cdb1ec0.
debug only of DEBUG flag is set
cleanup test 07
more documentation
add tests
fix bug in new()
bump to v0.10