add setMountpoint

- add getName()
- breaks build
add KS_END
remove exceptions

(belongs to refactor Backend commit before)
fix kdb tools for changes in libtools
bring KDB_O_CASCADING_NAME to kdb.h
renaming KDB_O_ -> KEY_

where needed
Merge branch 'tools'

- fix KEY_ names
- move them to kdb.h
- enhance Backend with mountpoint checks