Include default package config keys
Include default package config keys

The config keys that are currently initialized with the default value
are not added to user's `~/.atom/config.cson`. To ensure the same Atom
setup even when some default values are changed these are now included
in the `config.cson`. This includes keys for all core and community
packages.

Closes GH-124

arcticicestudio/igloo,arcticicestudio/igloo,arcticicestudio/igloo