chimera: update chimera (internal) API

the biggest chimera change since day-one: remove setXXX methods and
use FsInode#setStat() or JdbcFs#setInodeAttributes(). Lot of
removes....

Acked-by: Albert Rossi
chimera:  setInodeAttributes have to throw FileNotFoundChimeraException

Throw FileNotFoundChimeraException on attempt to update attributes of non existing inode.
Enable existing but disabled test cases to verify this functionality.

Allow size update only for regular files. Introduces two new exceptions:
IsDirChimeraException and InvalidArgumentChimeraException.

Acked-by:
Target: master
Require-book: no
Require-notes: no
remove sleeps from unit tests