Fix base() to apply font-size only once

The font-size property was being applied to both the html and body elements causing the % size reduction to occur twice, such that when font-size was set to 14px the actual type size was ~12px.
Update test for base() fix

The font-size property was being applied to both the html and body elements causing the % size reduction to occur twice, such that when font-size was set to 14px the actual type size was ~12px.
vertical-rhytm fix for small element
0.2.2
update test readme badge
update npm name in readme
add a note about docs
px as a string
sprite also
and all the others
big code cleanup, better docs and bugfixes

- improve internal docs, make formatting more consistent
- remove dollar signs before mixin names
- fix a variety of small bugs that worked their way in
fix for additive button mixin
fix a couple more bugs with dollar mixins
variety of small style and internal doc fixes
hr fix
Add import for nib

User should not need to import nib (a sub-dependency) manually when implicit: false
fix bug with field-error/warning/success
consistency and string over idents
remove vertial rhythm
Updated to Normalize v3.0.1