Add several parameters for web_checker recipe template.

There are use cases where not returning anything is okay.

modify workaround for bug in LibreOffice 3.5 so that it works with the system whose gcc is less than 4.5.

With Lib0 3.5 released, the issues found to convert some documents with versions 3.4 or less is not happening anymore.
Then, as Lib0 3.5 is working as expected and the commit e6481f91 is keeping the backward compatibility for cloudooo configuration, it will be revert and Lib0 will be installed in default installation

This reverts commit ad4fd161.

set 'default-zpublisher-encoding utf-8' otherwise we can have exception in Localizer with non iso-8859-15 characters. set other encoding variables as well.

Install is updatable, so it is safe to call it this way.

set GLIB_CFLAGS and GLIB_LIBS variables so that the initial compilation without having pkg-config works.

This reverts commit 168ca54c.

md5sum change was missing.

From changelog:

Make buildout.rmtree working with symlink as a path argument.
  https://bugs.launchpad.net/zc.buildout/+bug/144228