Minimal fixes to restructured text so that it renders properly on [pypi index page](https://pypi.org/project/slapos.core)

/reviewed-on nexedi/slapos.core!65

Because most txt were renamed as .rst, it makes sense to include all
.rst recursively

  Same as 1.4.12 but with a minor fix on the egg generation, after a rename of CHANGES.txt into CHANGES.rst

  Missing CHANGES.txt fails to install eggs.

Add ofset +0000 to utc date so after convert to another timezone it still remain valid.

/reviewed-on nexedi/slapos.core!63

Each tap will have a subnetwork with 16 more bits than the interface.
The IPv6 of the tap is the last of the subnetwork.

Note: the example IPv6 address is the address used in documentation (see https://en.wikipedia.org/wiki/IPv6_address#Documentation)

The bridge was never used anymore. For KVM software release, we are using tap with their own routes (packets are routes directly through the tap device).

checked with:
  pylint --disable all --enable spelling --spelling-ignore-words=URI,SSL,API,XXX,uninstall,initialize,slapgrid,slapformat,kvm,instantiation,IComputer,IException,Vifib,IRequester,ISupply,SocketError,virtio,boolean,traceback,http,mysoftwareproduct,foo,buildout --spelling-dict en_US slapos/slap/interface/slap.py

/reviewed-on nexedi/slapos.core!66

  The current code expected to have a string on the XML

In a scenario with multiple forms for the same software type it is better store which schema was used to render the form.

Use a light grey to blend nicer in the page.

Include "restricted_parameter", to hide values which are not part of the schema (but keep them as hidden) and don't allow to include new objects.

Include parameter to disallow raw editions

Fix ordering of the software types based on index definition

Wait until IPv6 is available on slapos interface before start slapos boot format.

/reviewed-on nexedi/slapos.core!62

- Monitor link on SlapOS interface will add OPML. New opml will be synced immediately then redirect to status view.
- Instances with subscription request can also request Slave Instances for frontends and others on shared computers.

/reviewed-on nexedi/slapos.core!61

Monitor link on SlapOS interface will add OPML. New opml will be synced immediately then redirect to  status view.

Instances with subscription request can also request Slave Instances for frontends and others on shared computers.

This allow configure more precisely the Capacity Quantity for an instance based on its software type.

It's not needed to show destroyed Software Installation in "Supplied Softwares" list which only make the research more harder.