Clean out flymake, which I never use.
Replace home-brewed stuff with smart tab package.
Only use smart tabs in programming language modes.
Disable linum and yasnippet in w3m.
Remove any non-base python modes.

Good riddance, so many unnecessary, out-of-date modes!
Remove redundant line.
Apparently markdown-mode cares about trailing w.s.
Omit line numbers in all shell modes.
Deactivate feature: it's broken on my system.

I don't have a default scss compiler installed, so I don't need to do
this every time I save a file.  Also it throws an error message if you
don't.
Add some paths.
Clean-up customize-set-variables/faces.

Remove unused stuff, whitespace adjustments, etc.