Bug 26245: Remove unused functions from members.js

Bug 26245: Remove unused functions from members.js

This patch removes some code from members.js which was unused.

To test, apply the patch and test that the process of adding or editing
a patron is unaffected. Check the Koha codebase for references to these
functions in JavaScript:

CheckDate
unique (note: Not the jQuery function)
check_manip_date
check_password

There should be none.

Signed-off-by: Brandon J <brandon.jimenez@inLibro.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>