Bug 18432: code comments assume male gender

Bug 18432: code comments assume male gender

Comments throughout the Koha codebase assume that
all librarians or borrowers are male by using the
pronoun 'he' universally. This patch changes to
'he or she' / 'him or hers'.

Testing plan:

- ensuring modifying tests still pass:
	+ C4/SIP/t/06patron_enable.t
	+ t/db_dependent/Circulation.t
	+ t/db_dependent/Koha/Patrons.t
	+ t/db_dependent/Reserves.t

Sponsored-By: California College of the Arts
No code changes detected.
Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>