Add conf_mount_rw calls on functions that changes user/groups. It fixes #3294
Update zoneinfo to 2013.h
Teach system_timezone_configure() to deal with symlinks to avoid having timezone misconfigured. This fixes #3293
Prevent a Fall Back Pool from being selected when the DNS protocol is in use. If one is present in the config, ignore it. Fixes #3300
Revert "Add conf_mount_rw calls on functions that changes user/groups. It fixes #3294"

This reverts commit b1e5a286bb47d7e4a5b3d589cc27b557b3b13c41.
Call conf_mount_rw before delete user, a better fix for #3294