.gitconfig: Add alias to merge GitHub pull request

Ref. https://help.github.com/articles/checking-out-pull-requests-locally

Closes #422.
Brewfile: add some CTF tools

See https://github.com/ctfs/write-ups for more info.
Brewfile: add binutils and cifer
.osx: Disable transparency in the menu bar and elsewhere on Yosemite
.osx: Remove a few commands that no longer have any effect in Yosemite

Closes #436.
.osx: Use the system-native print preview dialog in Chrome

Closes #434.
.aliases: Update `npm` the right way

`npm install npm -g` is the new recommended way to update npm as specified in the npm-faq at https://github.com/npm/npm/blob/master/doc/misc/npm-faq.md.

Closes #423.
.osx: Don’t send Safari search queries to Apple
.osx: Make Yosemite Safari more useful
Use `brew.sh` instead of `Brewfile`

Also, remove `Caskfile` since I didn’t use it.

Closes #428.
.bash_profile: Support multiple hosts in SSH completion

Useful in cases such as:

```

Host vm1 vm2 vm3 vm4
     Host localhost
     # ...
```

Simply adding a `-` to `tr` fixes this.

Closes #437.
.vimrc: Enable `g:solarized_termtrans`

It improves the display in OS X Terminal.app.

http://ethanschoonover.com/solarized/vim-colors-solarized

Ref. #425.
brew.sh: Use `--with-iri` for `wget`

The older `--enable-iri` flag is deprecated.

Closes #445.
.exports: Remove `export HOMEBREW_CASK_OPTS`

It’s not needed anymore now that the `Caskfile` has been removed.

Closes #446.
.aliases: Remove npmjs.eu reference

See the deprecation notice: http://npmjs.eu/

Closes #448.