Bug 18502: Make koha-shell set the right PERL5LIB on dev installs

Bug 18502: Make koha-shell set the right PERL5LIB on dev installs

Bug 16749 introduced a nice way to have flexible paths. During the discussion on how to do it, we moved from having it contain the path to the git dir to just a boolean. The 'koha-shell' script didn't get attention it seems, and it is broken on dev installs.

This was hidden by the fact that many of us run dev installs on kohadevbox, which sets a .bashrc file for de instance's user, containing the right path when opening the new shell.

This patch changes the logic so on a dev install, intranetdir is picked as the right path. This is how it is handled in koha-functions.sh

To test:
- On kohadevbox, run:
  $ sudo koha-shell kohadev -c "perl misc4dev/populate_db.pl"
=> FAIL: C4/Installer.pm not found on PERL5LIB error.
- Apply this patch
- Replace /usr/bin/koha-shell with debian/scripts/koha-shell
  $ sudo cp kohaclone/debian/scripts/koha-shell /usr/bin/koha-shell
- Run:
  $ sudo koha-shell kohadev -c "perl misc4dev/populate_db.pl"
=> SUCCESS: No warning about missing libs is raised.
- Sign off :-D

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>