brew: update Brewfile
brew: update Brewfile

New dump, taken using `brew bundle dump` and then sorted.

Added:

- httping: for web perf measurement.
- httrack: for mirroring websites (sigh; it doesn't seem to work so
  well).
- potrace: no memory of why I installed this, but it is nifty.
- xquartz: dependency for screengif (a RubyGem).

Removed:

- flow: using locally installed `flow-bin` NPM packages instead.
- nvm: I'm using n instead nowadays.
- watchman: clashes with Chef-managed corporate version.

Changed:

- objective-caml -> ocaml
- tmux -> tmux [HEAD] (needed to mitigate El Capitan notifyd bug)

wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent