On bug 17591 we discovered that there was something weird going on with
the way we export and use subroutines/modules.
This patch tries to standardize our EXPORT to use EXPORT_OK only.

That way we will need to explicitely define the subroutine we want to
use from a module.

This patch is a squashed version of:
Bug 17600: After export.pl
Bug 17600: After perlimport
Bug 17600: Manual changes
Bug 17600: Other manual changes after second perlimports run
Bug 17600: Fix tests

And a lot of other manual changes.

export.pl is a dirty script that can be found on bug 17600.

"perlimport" is:
git clone https://github.com/oalders/App-perlimports.git
cd App-perlimports/
cpanm --installdeps .
export PERL5LIB="$PERL5LIB:/kohadevbox/koha/App-perlimports/lib"
find . \( -name "*.pl" -o -name "*.pm" \) -exec perl App-perlimports/script/perlimports --inplace-edit --no-preserve-unused --filename {} \;

The ideas of this patch are to:
* use EXPORT_OK instead of EXPORT
* perltidy the EXPOR...