Added upload_cache_url and upload_dir_url:
 - upload_cache_url: the value must be the url of shacache used to
   upload
   content.
 - upload_dir_url: the value must be the url of shadir used to upload
   the
   information about the content.

Also, the signature_private_key_file is not required to instanciate a
Software object, then it can be None by default.

All these parameters listed above should only be used in the buildout
command line, if they are not None. And it should be defined under
networkcache-section.

By default the buildout's options are written with '-' instead of '_'.

So, lets keep like that.

Removed the argument signature_public_file because it should be inside
the software profile under networkcache-section.

And renamed signature_private_file to signature_private_key_file.

Title is humand related name of computer, and reference is used by SlapOS
configuration.

Use My Acccount web section to expose buttons to request and revoke certificate.
Move out credentials management to button.
Reuse existing WebSection_viewMyAccountRender.

This supports configuration, when bridge cannot be attached with IPv6 capable
interface (like a lot of WLAN interfaces and IPv6 tunnels).

Thanks to setting ipv6_interface in slapformat configuration file, IPv6
generation will be done there, but IPv4 will be still available on bridge.

Users shall be able to instantiate software instances on their computers. This
is the most often found scenario (add *my* computer and instantiate on *it*
some software).

Add condition to support dictionary. This fix was needed to support Slave Instance inside parameter_dict because each Slave Instance is one dictonary

This commit also  fixes other arguments which were read  and parsed as regular
configuration files.

Previously, cert_file and key_file could  only be set from slapconsole section
but  as it's  supposed to  already been  defined in  slapos section,  then use
slapos values first, then fallback on slapconsole section.

slapconsole  should not fail  when there  is no  "slapconsole" section  in the
configuration file, as defaults should be enough.