Vim: Add backspace fix while inside of GNU Screen
Git: Use diff-highlight to show some inner diffs

Got the idea from:
https://coderwall.com/p/ydluzg

Made these changes via:

    $ for att in log show diff; do \
    git config --global pager.$att "diff-highlight | less"; \
    done
Vim: Use new diff programs for related keybindings

colordiff and diff-highlight just made my life better when I'm not using
Git.