Bug 18028: Remove outdated install_misc directory

Bug 18028: Remove outdated install_misc directory

This directory is no longer maintained and contain outdated information
on how to install Koha.
On the Internet there are tutos using them and that can create confusion
to new user (yes it could be confusing as well to execute a file that
does no longer exist).

NOTE: last tweak was mid 2016, but before that 2015. So I agree with
      the deletion.

Signed-off-by: Mark Tompsett <mtompset@hotmail.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Brendan A Gallagher <brendan@bywatersolutions.com>