Add support for sub-themes

e.g.

```
baseFontSize: '16px'
subThemes: {
  blog: {
    baseFontSize: '18px'
    bodyFontFamily: 'Open Sans'
}}
```

Author: KyleAMathews

package.json

@@ -12,7 +12,12 @@
     "gray-percentage": "^1.1.2",
     "is-array": "^1.0.1",
     "is-string": "^1.0.4",
-    "modularscale": "^1.0.2"
+    "isobject": "^1.0.0",
+    "lodash": "^3.9.3",
+    "modularscale": "^1.0.2",
+    "object-assign": "^3.0.0",
+    "shallow-copy": "0.0.1",
+    "shelljs": "^0.5.3"
   },
   "devDependencies": {
     "chai": "^3.0.0",
@@ -30,7 +35,6 @@
     "node-libs-browser": "^0.5.2",
     "object-assign": "^3.0.0",
     "parse-unit": "^1.0.1",
-    "pre-commit": "^1.0.7",
     "qs": "^3.1.0",
     "react": "^0.13.3",
     "react-headroom": "^1.6.1",
@@ -47,8 +51,7 @@
     "webpack-dev-server": "^1.9.0"
   },
   "directories": {
-    "example": "examples",
-    "test": "test"
+    "example": "examples"
   },
   "homepage": "https://github.com/KyleAMathews/react-typography",
   "keywords": [
@@ -65,8 +68,6 @@
     "url": "https://github.com/KyleAMathews/react-typography.git"
   },
   "scripts": {
-    "test": "node_modules/.bin/coffeelint test/* & NODE_ENV=test node_modules/.bin/mocha --recursive --compilers coffee:coffee-script/register -R mocha-unfunk-reporter",
-    "test-watch": "NODE_ENV=test node_modules/.bin/mocha -w --recursive --compilers coffee:coffee-script/register -R mocha-unfunk-reporter",
     "watch": "./node_modules/.bin/webpack-dev-server --hot"
   }
 }

src/components/GoogleFont.cjsx renamed to src/components/GoogleFont.coffee

@@ -18,10 +18,10 @@ module.exports = (options) ->
       fontsStr = fonts.join('|')
 
       if fontsStr
-        <link
-          href="//fonts.googleapis.com/css?family=#{fontsStr}"
-          rel="stylesheet"
-          type="text/css"
-        />
+        React.DOM.link({
+          href: "//fonts.googleapis.com/css?family=#{fontsStr}"
+          rel: "stylesheet"
+          type: "text/css"
+        })
       else
         null

src/components/TypographyStyle.cjsx renamed to src/components/TypographyStyle.coffee

@@ -10,7 +10,8 @@ module.exports = (styles) ->
     displayName: "TypographyStyle"
 
     render: ->
-      <style
-        id="typography.js"
-        dangerouslySetInnerHTML={{__html: styles}}
-      />
+      React.DOM.style({
+        id: "typography.js"
+        dangerouslySetInnerHTML:
+          __html: styles
+      })

src/index.coffee

@@ -1,10 +1,14 @@
 React = require 'react'
-objectAssign = require('react/lib/Object.assign')
+objectAssign = require('object-assign')
 VerticalRhythm = require 'compass-vertical-rhythm'
 ms = require 'modularscale'
 isArray = require 'is-array'
+isObject = require 'isobject'
+copy = require 'shallow-copy'
 
-module.exports = (options) ->
+createStyles = require('./utils/createStyles')
+
+module.exports = test = (options) ->
   defaults =
     baseFontSize: '18px'
     baseLineHeight: '28.5px'
@@ -24,14 +28,23 @@ module.exports = (options) ->
     boldWeight: 700
     fontFaces: []
 
-  options = objectAssign defaults, options
+  options = objectAssign(defaults, options)
+
+  if options.subThemes? and isObject(options.subThemes)
+    for name, theme of options.subThemes
+      options.subThemes[name] = objectAssign(copy(options), theme, rhythmUnit: 'px')
 
   unless isArray options.modularScales
     options.modularScales = [options.modularScales]
 
+  # Create styles for base theme + each subtheme.
   vr = VerticalRhythm(options)
+  styles = createStyles(vr, options)
 
-  styles = require('./utils/createStyles')(vr, options)
+  if options.subThemes? and isObject(options.subThemes)
+    for name, theme of options.subThemes
+      vr = VerticalRhythm(theme)
+      styles += createStyles(vr, theme, name, options)
 
   return {
     options: options
@@ -49,3 +62,11 @@ module.exports = (options) ->
       node.innerHTML = styles
       document.head.appendChild(node)
   }
+
+#console.log test({
+  #baseFontSize: '16px'
+  #subThemes:
+    #blog:
+      #baseFontSize: '18px'
+      #bodyFontFamily: 'Open Sans'
+#}).styles