syslog-ng: alternative for logread

syslog-ng: alternative for logread

When the syslog-ng installed it records all messages to /var/log/messages.
This makes the default OpenWrt's ubox /sbin/logread useless and return nothing.

The logread script was added to the syslog-ng as a shim.
It's based on `tail /var/log/messages` and repeats basic options that the ubox logread have.
The script is installed instead of the /sbin/logread and this is causes an error.

Instead install it to /usr/libexec/logread.sh and specify as an alternative /sbin/logread.

The ubox logread also needs to be made as alternative in /usr/libexec/logread-ubox.

So we need to give it a separate name.
The most simple and clear would be logread-shell or just logread.sh.

Suggested-by: Andreas Gnau <andreas.gnau@iopsys.eu>
Signed-off-by: Sergey Ponomarev <stokito@gmail.com>