For sftp to work we need to define sftp "subsystem" on server side in
sshd speak. Sftp support in turn allows for sshfs to work.

NOTE

	Subsystem sftp internal-sftp

won't work because we are doing games with ForceCommand and reexecution
of "$SSH_ORIGINAL_COMMAND" (see previous patch for details).

2a733418 (slaprunner: replaces dropbear by openssh) switched slaprunner
sshd from dropbear to openssh (thanks for it once again) and used
ForceCommand to imitate login shell to be partitions `${bash:location}/bin/bash -l`.

For case when original ssh command is explicitly provided
("$SSH_ORIGINAL_COMMAND" is not empty) the code there tries to just
execute what was provided by caller.

However the reexecution is not completely correct as for cases when
origin command contains some quoting, 1 level of quotes is removed.

The case when I hit this in practice is git access to repositories over
ssh. When git wants to e.g. clone a repository it runs `git-upload-pack
quoted-path-to-repo.git` and fails this way:

```
$ GIT_TRACE=1 git clone ssh://host1/~/B.git
19:28:23.558858 git.c:350               trace: built-in: git 'clone' 'ssh://host1/~/B.git'
Cloning into 'B'...
19:28:23.572994 run-command.c:336       trace: run_command: 'ssh' 'host1' 'git-upload-pack '\''~/B.git'\'''
fatal: ''~/B.git'' does not appear to be a git repository
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.
```

Quoting SSH_ORIGINAL_COMMAND and evaluating it completely via eval fixes this.

/cc @Nicolas, @alain.takoudjou

Because this url is use by [erp5_promise](https://lab.nexedi.com/nexedi/erp5/blob/450ae11128503934b4d81de8c7c72ba7aa7948d5/bt5/erp5_promise/SkinTemplateItem/portal_skins/erp5_promise/Alarm_checkPromiseConversionServer.py#L5) to configure cloudooo in the preference, but erp5 preference is not supposed to be `cloudooo://` but just `http://` . 

FYI, this erp5_promise is the **Check Site Consistency** part described in the "ERP5 on webrunner" installation procedure as documented in https://www.erp5.com/erp5-HowTo.Request.Erp5.Instance.On.Slap.Os.Webrunner

/cc @tc @vpelletier 

/reviewed-on nexedi/slapos!94

It depends on RINA libraries installed system-wide, which in turn depend on
other libraries like libssl and zlib.

Slapos.toolbox has a new dependency to pycurl, which fails to compile if libcurl cannot be found. This commit adds the component/pycurl dependency to most of the Software Releases which have a dependency to slapos.toolbox.

I tried to do it globally, so I couldn't check the compilation of all the modified SRs. Is it a way to test that all SRs still compiled ?

Also, did I forget some important SR ?

@rafael @alain.takoudjou @kazuhiko @jm 

/reviewed-on nexedi/slapos!97