Alias view to "vim -R" when available
We already alias "vi" to "vim" when the vim-enhanced package is
installed. However, /usr/bin/view is a symlink to vi, which results in
inconsistent behavior between the two - the "vi" command runs in vim
mode, but the "view" command runs in vi mode. Alias "view" to "vim -R"
when vim-enhanced is available so that these are consistent.