add named feature for package configuration
ignore package install directory
enable ido mode
define a variable for required packages
add smex and configure keybinding
add named feature for feature configuration
remove cask and pallet packages
ignore auto-save-list directory
add directory for state files and ignore it
load feature configuration
configure saveplace
configure handling of backup files
set additional editor configuration options
move backup directory into state directory
move smex save file into state directory
additional smex keybindings
open zsh files in sh-mode
disable some UI elements