diff_options: Remove non-equals argument value handling

Tested out diff arguments with Git, and it turns out that arguments in
the following form:

    $ git diff --word-diff color

are not allowed. This error results:

    fatal: ambiguous argument 'color': unknown revision or path not in the working tree.
    Use '--' to separate paths from revisions, like this:
    'git <command> [<revision>...] -- [<file>...]'

Thus, option all arguments require the equals character to specify the
value of those arguments.

We can make the logic much simpler by eliminating handling of
space-separated argument values altogether.

This fixes the problem of suggestion positional arguments being
misinterpreted as `OPT_OPTIONS` argument values.

0 files changed, 0 insertions, 0 deletions