Use Debian jessie or xenial-proposed as backports in trusty?

[Ralf Mardorf]

On Tue, 5 Apr 2016 12:38:03 +0100, Colin Watson wrote:
>libfoo_bar.so.1* would be in a libfoo-bar1 package, while
>libfoo_bar.so.2* would be in a libfoo-bar2 package, and the two should
>be coinstallable.

Ok, the Ubuntu package name scheme is soname related, this makes sense
and it's easy to understand.

To what is the package version number related, e.g. what is

1.4.0 for, if the lib is 2.0.0?

[root at archlinux rocketmouse]# systemd-nspawn -qD /mnt/moonstudio dpkg -l libvpx2|grep ii
ii  libvpx2:amd64  1.4.0-4      amd64        VP8 and VP9 video codec (shared library)
[root at archlinux rocketmouse]# systemd-nspawn -qD /mnt/moonstudio dpkg -L libvpx2|grep so
/usr/lib/x86_64-linux-gnu/libvpx.so.2.0.0
/usr/lib/x86_64-linux-gnu/libvpx.so.2
/usr/lib/x86_64-linux-gnu/libvpx.so.2.0

If it's not related to libs, what is the number behind app names for?
e.g. "ardour3" for /usr/bin/ardour4?

http://packages.ubuntu.com/wily/amd64/ardour3/filelist

Regards,
Ralf