osx_setup: remove old settings and fix broken ones.
osx_setup: add Activity Monitor settings.
osx_setup: remove more broken commands.
bootstrap.sh: add the -P option to pwd.
brew_setup: install the Getmail mail retriever.
brew_cask_setup: install Java.
brew_cask_setup: install 1Password.
osx_setup: allow the tab key to move between links in Safari.
brew_cask_setup: remove downloaded files.
Create .bash_aliases and source it if it exists.
Move the hub alias into .bash_aliases.