We don't need a section here, we inherit this from jupyter stack

gcc-5.5 compiles a bit slower python and we are observing failures in
ERP5 performance tests.

This is a loop invariant.

PyPDF2 must not overwrite showwarning because it breaks ERP5. ERP5 already overwrites it properly

https://github.com/mstamy2/PyPDF2/issues/67#issuecomment-34387142

This reverts commit de1e9ea0.

2.7.1+slapos006 revealed a bug in buildout bug, breaking resilient KVM.

The only change should be the upgrade of rdiff-backup
(from 1.0.5+SlapOSPatched001 to 1.3.4nxd6-SlapOSPatched001)
for some SR that extend the resilient stack.

For some SR, it implies the following upgrades:
- decorator: 4.3.0
- gitdb2: 2.0.5
- smmap2: 2.0.5
- subprocess32: 3.5.3

This is required for Python 3.7

As SOFTWARE_HOME is added at the top of sys.path, this meant that Zope2.egg/Zope2
ended up at the top of sys.path:
  * This broke `imp.find_module('App')` and Pylint (`No name 'Extensions' in
    module 'App' (no-name-in-module)`) because there are `App` modules in both
    Zope2.egg/Zope2/ and Zope2.egg/ and the former was returned.
  * "Normal" instances and Products.ERP5Type.tests.runUnitTest properly set up
    SOFTWARE_HOME to Zope2.egg/.

Additionally, according to Zope2/Testing documentation, SOFTWARE_HOME is only
needed to find Zope2.egg/Testing module, already available as Zope2.egg is in
sys.path.

Mariadb was not shared, because installing mroonga writes a plugin in
mariadb's plugin dir and it's not allowed for one part to write in
another part's folder.

The approach is to install mroonga plugin in it's own plugin directory,
then copy all mariadb default plugins in this plugin directory and
configure instance to use mroonga's plugin directory.

Groonga also has plugins and we are using groonga-normalizer-mysql
plugin. Fortunately, groonga reads plugins located in paths listed in
GRN_PLUGINS_PATH environment variable, so we can use a simpler approach
of installing plugins in their own installation folder and set
GRN_PLUGINS_PATH in the environment of processes using groonga, ie. the
mariadb server process.

We now need to refer to the part where the dictionnary was installed.

apr and apr-util are now build separately. I'm not sure there was any
benefit with that approach of copying the directories inside apache
source tree before build.

Using extra modules, like apache-antiloris require to install apache in
non-shared mode.

This also removes apache-antiloris from cloudooo and erp5 stacks so that
they can use apache as shared. Even if the section was installed, this
was not used anywhere.

log accesses (the logrotate conf already exists for them), and
remove the pattern "<IfDefine Port>" which was used when this
apache conf was extended by the software's apache extending
the monitor stack

TODO: There are still direct references to specific version of Python in:
  - slapos component
  - bazel templates
  - nextcloud & theia SR

if last_backup was an int, the script failed with this error:

result undefined, global datetime = <module 'datetime' from '/srv/slapgrid/
slappart6...6d33cee74/lib/python2.7/lib-dynload/datetime.so'>,
datetime.datetime = <type 'datetime.datetime'>,
datetime.datetime.fromtimestamp = <built-in method fromtimestamp of type
object>, last_backup = '1587724103'
<type 'exceptions.TypeError'>: a float is required
      args = ('a float is required',)
      message = 'a float is required'