.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.
Merge commit '128bb08e3ebb0eebfad8fb77ad32fd05c89171a7'

* commit '128bb08e3ebb0eebfad8fb77ad32fd05c89171a7':
  .aliases: Update `npm` the right way
  .osx: Use the system-native print preview dialog in Chrome
  .osx: Remove a few commands that no longer have any effect in Yosemite
  .osx: Disable transparency in the menu bar and elsewhere on Yosemite