This reverts commit 22a38bd0.

This reverts commit 9715449d.

This reverts commit d1452403.

slapos node software fail with:

```
We have no distributions for lxml that satisfies 'lxml==3.7.3'.
Building lxml version 3.7.3.
Building without Cython.
ERROR: /bin/sh: 1: xslt-config: not found

** make sure the development packages of libxml2 and libxslt are installed **

Using build configuration of libxslt
Compile failed: command 'gcc' failed with exit status 1
*********************************************************************************
Could not find function xmlCheckVersion in library libxml2. Is libxml2 installed?
*********************************************************************************
An error occurred when trying to install lxml 3.7.3. Look above this message for any errors that were output by easy_install.
While:
  Installing.
  Getting section instance-profile.
  Initializing section instance-profile.
  Getting section proftpd-output.
  Initializing section proftpd-output.
  Getting option proftpd-output:command.
  Getting option proftpd-output:proftpd.
  Getting section proftpd.
  Initializing section proftpd.
  Getting option proftpd:environment.
  Getting section proftpd-userinfo.
  Initializing section proftpd-userinfo.
  Installing recipe slapos.cookbook.
Error: Couldn't install: lxml 3.7.3
```

/reviewed-on nexedi/slapos!308

https://sourceware.org/glibc/wiki/Release/2.26#Removal_of_.27xlocale.h.27

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81712

monitor: move scripts wrapper and logrotate conf to buildout, uses some new promises from slapos.toolbox

monitor was updated in slapos.toolbox to not generate promise launcher scripts anymore. All
generated scripts are now in buildout.
Monitor promise run script is removed from cron, slapgrid is used to run promises.
Replace some old promises by the new ones from slapos.toolbox. Cleanup monitor configuration.
Monitor report and monitor-promises directory are now obsolete.

Update verion of lab.nexed.com/kirr/neo.git used and all of its dependencies.

NEO/go now uses 2 Cgo packages:

- github.com/gwenn/gosqlite, and
- github.com/DataDog/czlib

and github.com/soheilhy/cmux to multiplex NEO & HTTP traffic on the same port.

Otherwise it is straighforward update which transitively pulled some more
dependencies.

The most convenient way to discover CFLAGS/LDFLAGS when building Cgo bits is
via pkg-config:

    https://golang.org/cmd/cgo/

For this to work let's add pkg-config to be available there in gowork out of
the box, and provide users with a way to specify which C packages they want to
be there on gowork's $PKG_CONFIG_PATH, e.g. this way:

    [gowork]
    cpkgpath =
        ${sqlite3:location}/lib/pkgconfig
        ${zlib:location}/lib/pkgconfig

In buildout sources cpkgpath is specified as multiline - not one line with ":"
delimiters - with the idea that it should be easy to amend gowork.cpkgpath with "+="
in different places.

Upgrading passes python-2.7 compile and tests. Let's hope it will be ok
everywhere else.

Hello @alain.takoudjou  could you please try to build this branch. 

/reviewed-on nexedi/slapos!305