Title: Fix quoting of backslashes in custom checks with nagios core
Level: 2
Component: core
Version: 1.2.5i5
Date: 1403786142
Class: fix
Compatible: incomp

When you are using Nagios as montitoring core then backslashes contained
in <tt>custom_checks</tt> (Classical active and passive Nagios checks) would
be interpreted by Nagios. That way single backslashes would usually vanish
und you would have to duplicate them.

The Check_MK Micro Core never interpreted these backslashes so it was
transparent for the user.

This fix changes the behaviour of Check_MK in a way that also with the
Nagios core you need only one backslash. Backslashes are transparent
now.

<b>NOTE</b>: If you have custom checks that contain backslashes (for
example as part of names or passwords) then you need to remove
duplicate backslashes after this update!
