Preprocess known toggleable options arguments in filter_options

This ensures that options defined in ~/.tigrc won't override arguments
passed on the command line. For example, `tig --date-order` will disable
reading of `commit-order` from ~/.tigrc.

Furthermore, toggling will now toggle based on what was passed on the
command line. For example, `tig --ignore-all-space` will toggle to
`--ignore-some-space`.
Disable graph drawing for reverse log order

Fixes #127