ct: Add libct_container_uname() API call that sets host/domain-names

This one is dependent on CLONE_NEWUTS

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
libctd: Simplify responce sending for simple ones

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
libctd: Sanitation

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
pbunix: Merge pack_ct_req into pbunix_send_ct_req

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
rpc: Handle error codes from rpc properly

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>