Add settings collection
Add mrt:purecss package

Pure css is a lightweight modular css library. Read more att
http://purecss.io
Rename settings collection to `Setting`
Add test setting data when bootstraping
Add settings form to admin view

This form cannot change anything as of now but displays the settings,
calues, default values etc. in a reasonable manner.
Update readme on where to admin the site
Add reactive-var package

To get some reactivity without Session variables.
Add saving and resetting settings

Create two buttons that can save and reset settings. Resetting a setting
will bring the `defaultValue` back.
Merge branch 'admin-settings'