.osx: Remove “increase window resize speed”

Sadly, this doesn’t work anymore in OS X 10.10.
README: Tweak `~/.path` example
brew.sh: Install speedtest_cli

Hat tip: @bramus – https://www.bram.us/2014/12/17/speedtest-cli/
.osx: Kill apps with `-HUP` to make sure they restart

Note that a full system restart is needed after running `.osx` anyhow, but this small change improves the situation for those who don’t do that.

Closes #469.
.osx: Revert to plain `killall` without `-HUP`

This reverts commit 07cd2632f56be58a5c1ba41a830e537e34f24e5f.

Ref. #469.
.gitconfig: Prevent showing files whose names contain non-ASCII symbols as unversioned

http://michael-kuehnel.de/git/2014/11/21/git-mac-osx-and-german-umlaute.html

Closes #460.
brew.sh: Fix copy-paste typo

Closes #472.
.osx: Add back the “increase window resize speed” hack

It didn’t work in OS X 10.10 anymore, but it seems OS X 10.10.1 does support it.

Ref. 4471e2732faede1d9b242cb547de8005578b3d10.
Merge remote-tracking branch 'upstream/master'

* upstream/master:
  .osx: Add back the “increase window resize speed” hack
  brew.sh: Fix copy-paste typo
  .gitconfig: Prevent showing files whose names contain non-ASCII symbols as unversioned
  .osx: Revert to plain `killall` without `-HUP`
  .osx: Kill apps with `-HUP` to make sure they restart
  brew.sh: Install speedtest_cli
  README: Tweak `~/.path` example
  .osx: Remove “increase window resize speed”