ctab.vim: http://www.vim.org/scripts/script.php?script_id=231

Imported by Dwayne Litzenberger <dlitz@dlitz.net>
Use ctab.vim for hard indents
Set sw=0 sts=-1 instead of setting them both to the value of 'ts'.

Should be functionally equivalent, but avoids problems for people who
set softtabstop=-1 in their .vimrc and expect the value to stick.
Don't allow setting softtabstop from securemodelines
Disable my busted gqip
Fix ctab.vim's handling to shiftwidth=0 softtabstop=-1

Also, see :help expression-syntax about using the if `? then : else`
operator:

    You should always put a space before the ':', otherwise it can be
    mistaken for use in a variable such as "a:1".

So, do that.
Makefiles getting softtabstop reset to 0 for some reason