more lightweight default install, added oh-my-zsh and some unix tooling

[bastiandoetsch]

• default to oh-my-zsh and only install git-together
• iterm config slightly different - bigger font, bigger window, powerline fonts
• don't install all those text editors, cloudfoundry, terraform by default
• default to no analytics, as there seems to be no-one maintaining this and it's not GDPR compliant anyways to auto-opt-in.

Beware: this opinionated towards me wanting a lightweight setup that doesn't install too many apps, but delivers a good command line experience

Feel free to request changes to this PR if something is out-of-line or doesnt' work...

[joemoore]

base oh-my-zsh added from previous commit.

Will use this PR as inspiration for various script splitting.

[joemoore]

Based on our past conversations I am closing this PR but do know that I am watching your fork and taking cues from it.