Bug#837880: vim: Unable to globally disable mouse

[Tim Small]

Package: vim
Version: 2:8.0.0003-1+b1
Followup-For: Bug #837880

mouse=a is now unconditionally set in /usr/share/vim/vim80/defaults.vim

As this is sourced after /etc/vim/vimrc this takes precedent.

Would be good if this could be fixed (i.e. to honour /etc/vim/vimrc), but
I'm not really sure what the best solution is myself.

-- Package-specific info:

--- real paths of main Vim binaries ---
/usr/bin/vi is /usr/bin/vim.gtk
/usr/bin/vim is /usr/bin/vim.gtk
/usr/bin/gvim is /usr/bin/vim.gtk

-- System Information:
Debian Release: stretch/sid
  APT prefers unstable-debug
  APT policy: (500, 'unstable-debug'), (500, 'unstable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.7.0-1-amd64 (SMP w/1 CPU core)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages vim depends on:
ii  libacl1      2.2.52-3
ii  libc6        2.24-3
ii  libgpm2      1.20.4-6.2
ii  libselinux1  2.5-3
ii  libtinfo5    6.0+20160917-1
ii  vim-common   2:8.0.0003-1
ii  vim-runtime  2:8.0.0003-1

vim recommends no packages.

Versions of packages vim suggests:
pn  ctags        <none>
pn  vim-doc      <none>
pn  vim-scripts  <none>

-- debconf-show failed