ERP5: add xmlsec

This includes xmlsec, the C library and its python bindings in ERP5, using the latest versions that are compatible with python 2.

`1.3.9` is the latest version of the python bindings with python 2 support and `1.2.30` is the latest version of the C library compiling with this version of the python bindings.

See merge request !1272
9 jobs for feat/cloudooo in 0 seconds
Status Job ID Name Coverage
  External
passed Cloudooo.UnitTest-Master

passed ERP5.StandaloneDeploymentScriptTest-Debian.Stretch

00:37:15

passed SlapOS.Eggs.UnitTest-Master.Python2

00:12:58

passed SlapOS.Eggs.UnitTest-Master.Python3

00:14:50

passed SlapOS.KVM.ResilienceTest-Master

passed SlapOS.SlapRunner.ResilienceTest-Master

failed SlapOS.SlapRunner.ResilienceTest-Master.ERP5

03:24:57

passed SlapOS.Eggs.UnitTest-Master.Python2

passed SlapOS.Eggs.UnitTest-Master.Python3