Performance improvements

[childnode]

1. ioreg -l is very time expensive, better use ioreg -c AppleSmartBattery -r
   see also discussion in http://hints.macworld.com/article.php?story=20100130123935998
2. disable package manager queries per default

to sum up: startup is reduced by 500ms

[childnode]

for testing:

  -bash:$ brew unlink archey && brew install -v https://raw.githubusercontent.com/childnodeContribArch/homebrew/performance/Library/Formula/archey.rb

[obihann]

@childnode So it seems that #38 is caused by this, though ioreg -c AppleSmartBattery -r is faster it has broken the test that we do to ensure their is a real battery status, since machines like Mac Pro's don't have batteries. I'm going to see what I can do so that we hopefully can keep this improvement.