Update design doc to match implementation
Update design doc to match implementation

This patch contains some minor changes in the design doc
to make sure the details match the implementation.

Signed-off-by: Helga Velroyen <2d0126b1ec6f9ec5cbec4a7012aa14faeaef10f5@google.com>
Reviewed-by: Hrvoje Ribicic <be5828fca31f89218048bec4189e30a581aa65da@google.com>

bitemyapp/ganeti,leshchevds/ganeti,yiannist/ganeti,grnet/snf-ganeti,onponomarev/ganeti,ganeti-github-testing/ganeti-test-1,mbakke/ganeti,yiannist/ganeti,grnet/snf-ganeti,andir/ganeti,andir/ganeti,bitemyapp/ganeti,apyrgio/ganeti,mbakke/ganeti,yiannist/ganeti,ganeti/ganeti,apyrgio/ganeti,leshchevds/ganeti,andir/ganeti,leshchevds/ganeti,dimara/ganeti,ganeti-github-testing/ganeti-test-1,ganeti/ganeti,dimara/ganeti,onponomarev/ganeti,ganeti/ganeti,mbakke/ganeti