Prepare NEWS file for 2.11.0 rc1
Prepare NEWS file for 2.11.0 rc1

Add section for 2.11.0 rc1, document all changes since
beta1.

Signed-off-by: Helga Velroyen <2d0126b1ec6f9ec5cbec4a7012aa14faeaef10f5@google.com>
Reviewed-by: Thomas Thrainer <98bdeac947eb8ca18146e9ce7f092788ec242cd1@google.com>

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