M #-: Modify hook exits (#3828)
M #-: Modify hook exits (#3828)

- Remove rescue SystemExit
- Apply unlock before each exit
- Changes on some comments and debug lines
atodorov-storpool/one,atodorov-storpool/one,baby-gnu/one,atodorov-storpool/one,atodorov-storpool/one,atodorov-storpool/one,atodorov-storpool/one,baby-gnu/one,baby-gnu/one,baby-gnu/one,baby-gnu/one,OpenNebula/one,atodorov-storpool/one,OpenNebula/one,atodorov-storpool/one,atodorov-storpool/one,OpenNebula/one,OpenNebula/one,OpenNebula/one,OpenNebula/one,OpenNebula/one,baby-gnu/one,baby-gnu/one,OpenNebula/one,OpenNebula/one,baby-gnu/one